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Tile Calculator

Enter your area, tile size, and grout joint to get tiles, boxes, thinset bags, and grout pounds — with layout-pattern waste factors and trowel-notch coverage built in.

Thinset coverage per bag is from manufacturer technical data sheets (Custom Building Products, LATICRETE), at the conservative low end so you buy enough. Boxes are computed from the square feet per box on your label — not an invented count. For substrate flatness, waterproofing, or permit-required work, verify with your local building authority.

Quick Answer

A 12×12 ft floor in 12×12 straight-laid tile needs about 14 boxes at 12 sq ft per box (~10% waste for cuts), plus about 2 bags of thinset and 8.1 lbs of grout for a 1/8" joint. Per Custom Building Products VersaBond TDS-119, a 1/4" x 1/4" trowel covers about 85–95 sq ft per 50 lb bag (we use the conservative low end). Diagonal and herringbone layouts add about 15% waste. Use our tile calculator for an estimate from your room size, tile size, and box coverage.

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Plan View — Tile Grid & Grout Joints

Tile layout plan view — top-down grid of tiles with grout joints and area dimensions. Schematic top-down plan view of a tiled area laid as a straight grid (Straight grid (parallel to walls)). The gaps between the tiles are the grout joints; one tile is annotated with its length and width, and one joint is annotated with its width. Area length and width are dimensioned with arrows OUTSIDE the tiled outline per standard drafting convention. The 10% waste-factor callout indicates the cut tiles at the walls included in your order. Layer order validated against tile-retailer and manufacturer layout guides (The Tile Shop, Custom Building Products). Single tile (length × width) Grout joint width Length Width +10% waste at wall cuts Straight grid (parallel to walls)
  • Tiles (each length × width)
  • Grout joint (width between tiles)
  • Area length × width

Schematic top-down plan view — not to scale. For planning estimates only — verify substrate, layout, and any waterproofing requirement with your tile install guide before ordering.

Estimate your Tile

How to use this calculator

Seven inputs drive the calculation — the defaults match a typical 12×12 ft floor.

  1. Area — total area, or length × width to compute it.
  2. Tile size — common formats, or enter custom dimensions.
  3. Square feet per box — from your box label (boxes are computed from this).
  4. Layout — straight, diagonal, herringbone, or large-format (sets the waste factor).
  5. Trowel notch — bigger notch = fewer sq ft of thinset per bag.
  6. Grout joint width + grout type — sets grout pounds.
  7. Surface — floor, wall, or backsplash.

Start from a preset:

Each preset fills in a tile size, layout, and an example area (in feet) — change any field afterward.

Step 1 — Area to tile
Step 2 — Tile size
Step 3 — Box coverage
sq ft/box

Box counts vary by product line — always read the coverage off your box. Boxes needed are computed from this number.

Step 4 — Layout pattern

Straight ~10% waste; diagonal, herringbone, and large-format ~15% (more cuts).

Step 5 — Trowel notch (thinset)

Bigger tile needs a bigger notch — and a bag of thinset covers fewer square feet.

Step 6 — Grout joint + grout type
in

1/16" = 0.0625 · 1/8" = 0.125 · 3/16" = 0.1875 · 1/4" = 0.25

Step 7 — Surface

Floor tile typically uses a larger trowel notch and sanded grout than a wall or backsplash.

Your Estimated Tile Materials

14
 This estimate is based on tile sold by the box. Check price at Home Depot Check price at Amazon CraftedCalcs earns commission on purchases made through the Home Depot and Amazon links.
Boxes to buy
159
Tiles (approx.)
2 bags
Thinset (50 lb bags)
8.1 lbs
Grout (pounds)
Net area (before waste) 144 sq ft
Area to buy (with waste) 158 sq ft
Waste factor 10% waste factor (overage)
Thinset coverage used 80 sq ft / 50 lb bag

Your configuration

Area
144 sq ft
Length
12 ft
Width
12 ft
Tile size
12 × 12 in
Box coverage
12 sq ft/box
Grout joint
0.125 in

Need a reference? See common room sizes lookup table →

Shopping List

Affiliate disclosure: CraftedCalcs earns commission on purchases made through the Home Depot and Amazon links below. The commission doesn't change your price. It helps us keep this site free.

Quantities reflect your current calculator inputs. Verify against your box label's coverage and your bag's coverage before ordering.

What Else You'll Need

Calculator output covers the headline material. This list is the full bill — the fasteners, brackets, sealants, and safety hardware beginners typically forget to buy on the first trip.

Estimate only — not a professional bill of materials. It is NOT professional engineering, architectural, or contracting advice; NOT a code-compliance certificate; NOT a building permit application; and NOT a substitute for review by a licensed professional. Verify every quantity against your actual cut list, site conditions, and local building authority before purchasing. See our full disclaimer for details.

Tile + setting materials

  • Tile (ceramic / porcelain / stone), by the box Home Depot Amazon
    Qty: 14 boxes for a 12×12 ft floor at 12 sq ft/box, straight layout (includes 10% waste) — update for your box coverage · Read the square feet per box off the label — box counts are specific to each product line, so there is no universal tiles-per-box number. Order from one production run (same shade/lot number) so color matches across boxes. Per The Tile Shop coverage guide, divide your project area (plus waste) by the box coverage and round up to whole boxes.
  • Thinset (thin-set) mortar, 50 lb bags Home Depot Amazon
    Qty: 2 bags — ~80 sq ft per 50 lb bag for a 1/4" x 1/4" square notch · Coverage per bag drops as the trowel notch gets bigger. Per Custom Building Products VersaBond TDS-119, a 1/4" x 1/4" square notch covers about 85–95 sq ft and a 1/4" x 3/8" notch about 60–67 sq ft per 50 lb bag; this calculator uses the conservative low end. Confirm coverage on your product's bag.
  • Grout (sanded / unsanded / epoxy) Home Depot Amazon
    Qty: About 8.1 lbs for a 1/8" joint on 12×12 tile — bag size varies, so confirm coverage on the label · Use sanded grout for joints 1/8" and wider, unsanded for narrower joints, epoxy for stain resistance. Per The Tile Shop coverage guide, grout consumption rises with joint width and tile size — buy about 10% extra and confirm bag coverage on your product label.
  • Tile spacers (joint-width sized) Home Depot Amazon
    Hold a consistent grout-joint width while the thinset sets. Buy spacers that match the joint width you entered above. Remove them before grouting.

Setting tools

Substrate + finishing

  • Cement backer board (substrate) · optional Home Depot Amazon
    A stable, flat, tile-rated substrate is required for a lasting install. Substrate flatness, deflection, and waterproofing are NOT checked by this calculator — verify the substrate and any waterproofing requirement against your tile and membrane install guides.
  • Grout sealer (cement grout) · optional Home Depot Amazon
    Cement-based grout (sanded / unsanded) is porous and benefits from a penetrating sealer after curing. Epoxy grout does not need sealing.
  • Edge trim / bullnose / transition strip · optional Home Depot Amazon
    Finishes exposed tile edges at counters, niches, and doorways. Measure each exposed edge run separately.

Affiliate disclosure: CraftedCalcs earns commission on purchases made through the Home Depot and Amazon links above. The commission doesn't change your price. It helps us keep this site free.

15 items across 3 categories. Quantities assume standard residential practice — adjust up for longer spans, complex geometry, or pro-grade specification.

Box count formula

Boxes = ⌈(area × (1 + waste_factor)) ÷ sq_ft_per_box⌉

The net area (length × width, or the total you entered) is multiplied by the waste factor — about 10% for a straight grid, 15% for diagonal, herringbone, or large-format. The area-with-waste is divided by the square feet per box from your box label and rounded up to the next whole box. Box counts are specific to each product line, so this calculator divides by YOUR box coverage rather than guessing a tiles-per-box number. Always round up — partial boxes are not sold at retail, and keeping one spare box of attic stock from the same lot protects against future repairs.

Source: The Tile Shop Thinset & Grout Coverage guide (coverage + waste guidance)

Thinset bags formula

Thinset bags = ⌈(area × (1 + waste_factor)) ÷ coverage_per_bag⌉

Thinset coverage per 50 lb bag depends on the trowel notch. Per Custom Building Products VersaBond TDS-119, a 1/4 x 1/4 square notch covers about 85–95 sq ft per bag and a 1/4 x 3/8 notch about 60–67 sq ft; LATICRETE 254 Platinum gives a 1/2 x 1/2 notch about 35–40 sq ft. This calculator uses the conservative low end of those manufacturer ranges so you buy enough, never short. Coverage drops further on uneven substrate, deep-pattern tile backs, and natural stone — confirm the coverage printed on your bag.

Source: Custom Building Products VersaBond TDS-119 + LATICRETE 254 Platinum Datasheet

Grout pounds formula

Grout (lb/sq ft) = ((L + W) ÷ (L × W)) × J × T × density ÷ 1728 × 144

Grout fills the joints, so the quantity comes from joint geometry: tile length (L) and width (W) in inches, joint width (J), tile thickness (T), and a verified grout material density (sanded ~104, unsanded ~86, epoxy ~100 lb per cubic foot). Wide joints on small tiles use far more grout than narrow joints on large tiles. The result is reported in pounds — not bags — because bag size varies by product, so confirm the coverage on your grout label. Buy about 10% extra to allow for substrate irregularity and over-grouting.

Source: The Tile Shop Coverage guide + verified grout material densities

Boxes by Layout Pattern

Same 12×12 ft floor at 12 sq ft per box, by layout pattern. Diagonal, herringbone, and large-format layouts add more waste than a straight grid because they create more non-reusable wall offcuts.

Layout Waste Area with waste Boxes
Straight (grid parallel to walls) 10% 158 sq ft 14 boxes
Diagonal (45° to walls) 15% 166 sq ft 14 boxes
Herringbone (interlocking offset) 15% 166 sq ft 14 boxes
Large-format (tiles ≥15") 15% 166 sq ft 14 boxes

How This Calculator Estimates

Area and waste. The net area is your bare surface — length × width, or the total square feet you entered. The area-to-buy adds the waste factor on top for the material lost to perimeter cuts, breakage, and culling. Per The Tile Shop coverage guide, a straight grid runs about 10%, while diagonal, herringbone, and large-format layouts run about 15% because their 45° and offset cuts produce triangular wall offcuts that cannot be reused.

Boxes, not tiles. Tile is sold by the box, and the count of tiles per box is specific to each product line — there is no universal tiles-per-box number. So the calculator divides your area-with-waste by the square feet per box from YOUR label and rounds up to the next whole box. The tile count shown is an approximation (area ÷ single-tile size); the box count is the number you actually order. Keep one spare box of attic stock from the same lot for future repairs.

Thinset by trowel notch. Per Custom Building Products VersaBond TDS-119 and LATICRETE 254 Platinum, a 50 lb bag of thinset covers fewer square feet as the trowel notch gets bigger: roughly 90 sq ft for a 3/16" V-notch, 80 sq ft for a 1/4" square, 60 sq ft for a 1/4" x 3/8" square, and 35 sq ft for a 1/2" square. The calculator uses the conservative low end of those ranges. Bigger and heavier tile needs a bigger notch — and therefore more thinset per square foot.

Grout by joint geometry. Grout fills the joints, so its quantity comes from joint width, tile size, and tile thickness, multiplied by a verified grout material density. Wide joints on small tiles use far more grout than narrow joints on large tiles. The result is given in pounds, not bags, because bag size varies by product — confirm the coverage on your grout label and buy about 10% extra. Per The Tile Shop coverage guide, sanded grout is used for joints 1/8" and wider, unsanded for narrower joints.

What this calculator checks vs. does NOT check

Checked by this calculator

  • Net area (total, or length × width)
  • Waste factor by layout (straight 10% / diagonal · herringbone · large-format 15%)
  • Boxes from your box coverage (always rounded up)
  • Thinset bags by trowel notch (conservative coverage)
  • Grout pounds by joint width × tile size × thickness × density

NOT checked — verify yourself

  • Substrate flatness and tile-rated backer board
  • Deflection (the L/360 floor-stiffness rule for tile)
  • Waterproofing / shower-pan membranes
  • Local building code or permit requirements
  • Manufacturer-specific install instructions for YOUR tile, mortar, and grout

This calculator estimates material quantities only — it does NOT verify substrate, deflection, or waterproofing, and does NOT certify code compliance. It is NOT a code-compliance certificate, NOT a building permit application, and NOT a substitute for review by a licensed professional. Always follow your product installation guides and confirm requirements with your local building department.

Common Mistakes — Tile

Errors that consistently cause a second store trip or a failed tile job.

"I ran out of tile and the new box doesn't match."
Cause: under-ordering, then buying a second batch from a different production run. Tile color and texture vary between lots, and higher shade-variation tile varies even within a lot. Per the CTASC ANSI A137.1 V-scale explainer, tile is rated V1 (uniform) through V4 (substantial variation); buy all your tile from one lot, add the full waste factor, and keep one spare box of attic stock from that same lot for future repairs.

"I bought the wrong amount of thinset for my big tile."
Cause: using small-tile coverage numbers for large tile. A bag of thinset covers far fewer square feet with a big trowel notch. Per Custom Building Products VersaBond TDS-119, a 1/4" x 1/4" notch covers about 85–95 sq ft per bag, but a 1/4" x 3/8" notch (common for 12"–16" tile) drops to about 60–67 sq ft. Pick the trowel notch that matches your tile size in the calculator so the bag count reflects the right coverage.

"I used a flat 10% waste for a herringbone floor and came up short."
Cause: applying the straight-grid waste factor to a high-cut pattern. Diagonal, herringbone, and large-format layouts produce more non-reusable offcuts at the walls. Per The Tile Shop coverage guide, plan about 15% for those patterns, and add more for small rooms or many corners. Select your actual layout in the calculator so the waste factor matches.

Tile Boxes by Room Size — Common Reference

Based on 12 sq ft per box (a common 12×12 floor-tile coverage; verify on your label). Straight layout = 10% waste; diagonal/herringbone/large-format = 15% waste. Use the calculator above for any other box coverage or layout.

Room sq ft With waste (straight 10%) Boxes straight With waste (15%) Boxes diagonal
40 sq ft 44 sq ft 4 boxes 46 sq ft 4 boxes
100 sq ft 110 sq ft 10 boxes 115 sq ft 10 boxes
144 sq ft 158 sq ft 14 boxes 166 sq ft 14 boxes
200 sq ft 220 sq ft 19 boxes 230 sq ft 20 boxes
300 sq ft 330 sq ft 28 boxes 345 sq ft 29 boxes
500 sq ft 550 sq ft 46 boxes 575 sq ft 48 boxes

All rows use 12 sq ft/box (check your box label — it may differ). ← Use the calculator above for your specific room →

Tile Terminology

10 terms — tile, box coverage, thinset, trowel notch, grout, grout joint, waste factor, layout pattern, shade variation (V-rating), backsplash.

Tile
A flat, hard-wearing surfacing unit — ceramic, porcelain, or natural stone — set into a bed of thinset mortar with grout joints between units. Tiles are sold by the box, and the coverage printed on every box label (square feet per box) is what you divide your project area by to get a box count. Common formats include 12×12 and 12×24 floor tile, 6×24 plank tile, 3×6 subway tile, and mosaic sheets. There is no universal tile-size-to-tiles-per-box table — box counts are specific to each product line, so always read the coverage from the box.

The Tile Shop Coverage Guide ↗ · Porcelain is a denser, lower-absorption subtype of ceramic; both are estimated the same way by this calculator (area ÷ coverage).

Box coverage (sq ft per box)
The square footage one box of tile covers, printed on the box label. Because box counts vary by tile size, thickness, and product line, this calculator does NOT guess a tiles-per-box number — instead you enter the coverage from your box, and boxes needed are computed as your project area (plus waste) divided by that coverage, rounded up to whole boxes. You cannot buy a partial box, so the calculator always rounds up.

The Tile Shop Coverage Guide ↗ · Order from one production run (same lot/shade number) so color and texture match across boxes; keep one spare box of attic stock for future repairs.

Thinset (thin-set mortar)
A cement-based adhesive mortar — sometimes called "thin-set" or simply "mortar" — that bonds tile to the substrate. It is spread with a notched trowel and combed into ridges that collapse under the tile to form a continuous bed. Coverage per bag depends on the trowel notch size: smaller notches spread thinner and cover more area per bag; larger notches (for bigger, heavier tile) spread thicker and cover less. This calculator uses conservative coverage figures per the manufacturer technical data sheets so you buy enough, never short.

Custom Building Products VersaBond TDS-119 ↗ · Coverage drops on uneven substrate, deep-pattern tile backs, and natural stone — confirm bag coverage on your specific product label.

Trowel notch
The size and shape of the teeth cut into a tiling trowel (for example 3/16" V-notch, 1/4"×1/4" square, 1/4"×3/8" square, or 1/2"×1/2" square). The notch meters how much thinset is laid down, which sets both the mortar bed thickness and how many square feet a bag of thinset covers. A general rule from manufacturer guidance: the bigger and heavier the tile, the bigger the notch — and the fewer square feet you get per bag.

LATICRETE 254 Platinum Datasheet ↗ · For large-format tile, many manufacturers recommend back-buttering (spreading thinset on the tile back too) for full coverage — verify in your tile and mortar install guides.

Grout
The material that fills the joints between set tiles, locking them together and sealing the surface. Sanded grout is used for wider joints (typically 1/8" and up); unsanded grout for narrow joints (under 1/8"); epoxy grout for stain and chemical resistance. The amount of grout you need depends on joint width, tile size, and tile thickness — wide joints on small tiles use far more grout than narrow joints on large tiles. This calculator reports grout in pounds because bag size varies by product.

The Tile Shop Coverage Guide ↗ · Grout consumption rises with substrate irregularity and over-grouting; buy about 10% extra and confirm bag coverage on your product label.

Grout joint
The deliberate gap left between adjacent tiles, later filled with grout. Joint width is a design and technical choice: narrower joints look cleaner but demand flatter tile and substrate; wider joints absorb size variation in the tile. Joint width directly drives grout quantity — the calculator multiplies the joint geometry (width × tile thickness, against the tile-perimeter ratio) by a verified grout density to estimate pounds of grout.

The Tile Shop Coverage Guide ↗ · Spacers hold a consistent joint width during setting; the minimum joint depends on the tile’s shade/size variation — verify with your tile’s install guide.

Waste factor (overage)
The percentage of extra tile you order above the measured area to cover perimeter cuts, breakage, and culling. This calculator applies field-practice values that rise with cut density: about 10% for a straight grid, and about 15% for diagonal, herringbone, and large-format layouts, which create more non-reusable offcuts. Always round up to whole boxes.

The Tile Shop Coverage Guide ↗ · For very small rooms, many corners, or intricate patterns, add more — waste varies with room shape and installer skill. Confirm against your own layout.

Layout pattern
How tiles are arranged relative to the walls: straight (grid parallel to walls — lowest waste), diagonal (45° to walls — more perimeter cuts), herringbone (interlocking offset — the most cut tiles), or large-format (straight, but tiles 15" and larger add breakage and flatness-culling overage). The pattern you choose drives the waste factor the calculator applies.

The Tile Shop Coverage Guide ↗ · Plank and subway tiles are usually run in a brick-offset; mosaic is bought and counted by the sheet, not by the individual chip.

Shade variation (V-rating)
A four-level scale describing how much color and texture vary from tile to tile within the same product: V1 (uniform), V2 (slight), V3 (moderate), V4 (substantial / random). The rating is published on the tile’s spec sheet. Higher-V tile benefits from dry-laying several boxes mixed together before setting, so the variation is distributed evenly across the floor rather than clustering.

CTASC ANSI A137.1 V-scale explainer ↗ · The V1–V4 scale comes from ANSI A137.1; we reference it via the Ceramic Tile and Stone Consultants (CTASC) explainer, which republishes the scale.

Backsplash
A tiled wall area behind a counter, sink, or range — typically a small surface laid with small-format or mosaic tile. Because a backsplash is a vertical, low-area surface, it is usually estimated separately from a floor: measure the wall length × height, subtract any window or outlet area, and treat it as its own tile order. This calculator’s surface mode (floor / wall / backsplash) lets you label the surface you are estimating.

The Tile Shop Coverage Guide ↗ · Wall and backsplash installs often use a smaller trowel notch and unsanded grout than a floor — verify against your tile and mortar install guides.

Frequently Asked Questions

How many tiles do I need for a room?

Measure the room length × width for the area, then add a waste factor for cuts — about 10% for a straight grid and 15% for diagonal or herringbone (always confirm against your layout) — and divide by your tile’s coverage. Per The Tile Shop coverage guide, tile is sold by the box, so the number you actually order is boxes: divide the area-plus-waste by the square feet per box printed on the label and round up to whole boxes (always round up — you cannot buy a partial box).

How many tiles are in a box?

There is no universal answer — box counts depend on the tile size, thickness, and product line, so two different 12×24 tiles can have different counts per box. That is why this calculator asks for the square feet per box (printed on every box label) instead of guessing. Enter that coverage and the calculator divides your area-plus-waste by it to get boxes. Per The Tile Shop coverage guide, the box coverage is the figure to divide by.

How much thinset do I need for tile?

Thinset coverage per 50 lb bag depends on the trowel notch. Per Custom Building Products VersaBond TDS-119, a 1/4" x 1/4" square notch covers about 85–95 sq ft per bag, and a 1/4" x 3/8" notch about 60–67 sq ft. LATICRETE 254 Platinum gives a 1/2" x 1/2" notch about 35–40 sq ft per bag. This calculator uses the conservative low end of those ranges so you buy enough; confirm coverage on your bag.

How much grout do I need for tile?

Grout quantity depends on joint width, tile size, and tile thickness — wide joints on small tiles use far more than narrow joints on large tiles. This calculator estimates pounds of grout from that joint geometry and a verified grout density, and reports pounds (not bags) because bag size varies by product. As insurance, buy about 10% extra — and always confirm bag coverage on your label per The Tile Shop coverage guide.

What size trowel notch should I use for tile?

As a rule from the mortar manufacturers, the bigger and heavier the tile, the bigger the trowel notch. A 3/16" V-notch suits mosaic and small wall tile; a 1/4" x 1/4" square notch suits standard 8"–12" floor tile; a 1/4" x 3/8" notch suits 12"–16" tile; and a 1/2" x 1/2" notch suits large-format and heavy tile. Per LATICRETE 254 Platinum, the larger the notch, the fewer square feet a bag of thinset covers.

How much extra tile should I buy for waste?

Plan on roughly 10% extra for a straight grid and about 15% for diagonal, herringbone, or large-format layouts, which create more non-reusable offcuts at the walls (always confirm against your own layout). Add more for small rooms, many corners, or intricate patterns. Per The Tile Shop coverage guide, keep one spare box of attic stock from the same lot for future repairs.

How do I calculate tile for a backsplash?

Treat a backsplash as its own small order: measure the wall length × height, subtract any window or large outlet area, add waste for cuts, then divide by your tile’s box coverage. Set the surface to "backsplash" in this calculator to label the estimate. Backsplashes often use small-format or mosaic tile, a smaller trowel notch, and unsanded grout — verify the specifics against your tile and mortar install guides.

Is this calculator for floor tile or wall tile?

Both — the surface selector (floor / wall / backsplash) lets you label whichever surface you are estimating. The math is the same in each case: area × waste factor ÷ box coverage for boxes, trowel notch for thinset bags, and joint geometry for grout. Wall and backsplash installs typically use a smaller notch and unsanded grout than a floor; confirm against your product install guides.

How many boxes of tile for a 10x10 room?

A 10×10 room is 100 sq ft. Add a straight-grid waste factor of about 10% (always confirm against your layout), which makes 110 sq ft. At 12 sq ft per box that rounds up to 10 boxes; at 15 sq ft per box it is 8 boxes; at 20 sq ft per box it is 6 boxes — always round up to whole boxes. Per The Tile Shop coverage guide, enter your room size and your box coverage in the calculator above for an estimate.

Does the calculator work for porcelain, ceramic, and stone tile?

Yes. Porcelain, ceramic, and natural stone are all estimated the same way: area × waste ÷ box coverage for the tile count, with thinset by trowel notch and grout by joint geometry. The main practical difference is that larger and heavier tile (common in porcelain and stone) calls for a bigger trowel notch and more thinset per square foot. Enter your tile size, box coverage, and trowel notch and the calculator handles all three materials.

Troubleshooting Tips

Common install and post-install tile issues. Click any item to expand.

"My tiles are cracking after install. What went wrong?"
Cracking after install usually points to a substrate that flexes too much or was not flat. Tile is rigid and needs a stiff, flat base — floor systems for tile are commonly built to the L/360 deflection rule, and the substrate should be a tile-rated backer board, not bare subfloor. Hollow spots from incomplete thinset coverage also concentrate stress and crack tiles underfoot. This calculator estimates quantities only; it does NOT check deflection or substrate flatness. Verify the substrate and any required membrane against your tile and backer-board install guides, and re-set any tile that sounds hollow when tapped.

"My grout is cracking or crumbling in the joints."
Grout cracks from one of a few causes: too much water in the mix (weakens the cured grout), movement in the substrate, or using the wrong grout for the joint width. Per The Tile Shop coverage guide, sanded grout is used for joints 1/8" and wider and unsanded for narrower joints — unsanded grout in a wide joint shrinks and cracks. Rake out the failed grout, confirm the substrate is stable, and re-grout with the correct type mixed to the label's water ratio. Movement joints (soft caulk) belong at changes of plane and at the perimeter.

"My tiles sound hollow when I tap them."
A hollow sound means incomplete thinset contact under the tile — voids that can lead to cracks or loose tiles. The usual causes are a trowel notch too small for the tile, not back-buttering large tile, or letting the thinset skin over before setting the tile. Per LATICRETE 254 Platinum, match the notch to the tile size; for large-format tile, back-butter the tile so the mortar fully fills behind it. Isolated hollow tiles can be removed and re-set; widespread hollowness usually means relaying with the correct notch and technique.

"My finished floor has lippage — tile edges sticking up."
Lippage — one tile edge higher than its neighbor — comes from an uneven substrate, inconsistent thinset, or large tile set without a leveling system. Big tiles are less forgiving, which is why a tile leveling system (clips and wedges) is worth using on 12×24 and larger. Once the thinset has cured, lippage can only be reduced by grinding or by removing and re-setting the high tiles on a flattened bed. Check substrate flatness before you start; this calculator does not check flatness.

"There's a white haze on my tile after grouting."
A white film after grouting is usually grout haze — a thin residue left when grout dries on the tile face. Remove it with a damp sponge and clean water within the first day or two, or with a manufacturer-approved grout-haze remover for stubborn film. Avoid acidic cleaners on natural stone and on polished tile unless the cleaner is rated for them. Buffing with a dry microfiber cloth after the haze remover lifts the last of the film.

"My grout color came out uneven and blotchy."
Blotchy cement grout is most often caused by inconsistent water in the mix from batch to batch, or by wiping the joints with too much water during cleanup, which pulls pigment unevenly. Mix every batch to the same water ratio, let the grout cure fully, and avoid over-washing. A pigmented grout sealer or a grout-refresh colorant can even out minor blotchiness; severe cases may need the grout raked out and replaced. Epoxy grout avoids this because it does not depend on water curing.

"Water is getting under my shower tile."
Tile and cement grout are not themselves waterproof — wet areas rely on a waterproofing membrane or pan behind and beneath the tile. If water is getting through, the membrane, pan, or the seal at changes of plane is likely the problem, not the grout alone. This calculator estimates tile, thinset, and grout quantities only; it does NOT check or size waterproofing. For showers and other wet areas, follow your membrane manufacturer's system and confirm requirements with your local building department before re-tiling.

"I bought too few boxes and the store is out of my lot."
When you run short, a fresh batch may carry a slightly different shade or texture. Per the CTASC ANSI A137.1 V-scale explainer, this is most noticeable on V3 and V4 tile. To blend a new lot, dry-lay tiles from the old and new boxes mixed together across the field so the difference is distributed rather than forming a visible seam. Going forward, order the full waste factor up front and keep a spare box of attic stock from the original lot.

"My thinset is drying before I can set the tile."
Thinset that skins over before the tile is placed will not bond — you will get hollow spots. Spread only as much thinset as you can tile within its open time, work in smaller sections, and re-comb thinset that has started to skin. Hot, dry, or windy conditions shorten open time. Per Custom Building Products VersaBond TDS-119, follow the mortar's open-time and pot-life guidance; press each tile in with a slight twist to collapse the ridges and check coverage by lifting a tile periodically.

"My tile layout ends in a thin sliver at one wall."
A thin sliver cut at a wall looks unbalanced and is fragile. The fix is in the layout, not the order: dry-lay the field from the center of the room (or the most visible sight line) so the cuts at opposite walls are roughly equal and at least a half-tile wide. Snapping reference lines before spreading thinset prevents the run from drifting. The calculator's waste factor covers the cut tiles; planning the starting point is what avoids the sliver.

"My natural stone tile is staining and etching."
Many natural stones (marble, travertine, limestone) are porous and acid-sensitive — they stain from spills and etch from acidic cleaners or foods. Seal porous stone with a penetrating sealer before grouting and on a maintenance schedule afterward, and clean only with a pH-neutral, stone-safe cleaner. Stone also commonly needs white thinset (gray can show through translucent stone) and careful handling for shade variation. Follow the stone supplier's sealing and cleaning guidance for your specific material.

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Last updated 2026-06-27 · Formula sources: Custom Building Products VersaBond TDS-119 · LATICRETE 254 Platinum · The Tile Shop coverage guide · AI-assisted content disclosure · © 2026 Madabusi Ventures LLC