Tile Calculator
Free tile and flooring calculator: enter the area, tile size, and grout joint to see how many tiles to buy, plus whole boxes from the count or coverage printed on the box.
- Updated October 2026
12 × 12 in tiles · 10% allowance
130tiles
Boxes
—
Add the box size
Area
120 sq ft
132 sq ft with allowance
- Tile face
- 1 sq ft
- Per tile incl. 1/8 in joint
- 1.021 sq ft
- Exact tiles before rounding
- 129.29
Area-based estimate: it does not plan the layout or guarantee that cut pieces can be reused.
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AnswerTiling 120 sq ft with 12 × 12 in tiles and 1/8 in grout joints, plus a 10% allowance, takes 130 tiles.
How to use this tile calculator
- Enter the floor or wall length and width, or switch to total area.
- Enter the tile size and the grout joint you plan to use. Use the actual tile size from the box.
- Set a waste allowance for cuts, breakage, and spare tiles. There is no single standard; diagonal and patterned layouts need more.
- Optionally, enter tiles per box or coverage per box, from the box or product page, to see whole boxes.
How to calculate tiles: the formula, shown
Each tile covers its own face plus one grout joint in each direction. Divide the area to tile (plus your allowance) by that footprint and round up to whole tiles. If you enter the box size, the calculator also rounds up to whole boxes.
Default example. A 12 × 10 ft floor, 12 × 12 in tiles, 1/8 in grout joints, and a 10% allowance. No box size is assumed: tiles per box and coverage per box differ between products. Change the inputs above and the result panel recalculates; this worked example always shows the default.
Area = 12 ft × 10 ft = 120 ft² Allowance = 120 × (1 + 10/100) = 132 ft² Per tile = (12 + 0.125) in × (12 + 0.125) in ÷ 144 = 1.0209 ft² Tiles = 132 ÷ 1.0209 = 129.29 → 130 tiles Boxes = tiles ÷ tiles per box, rounded up (enter your box)
Leaving the grout joint at 0 gives a slightly higher, more cautious tile count. If you use coverage per box instead of tiles per box, the box count uses the area with allowance, because the coverage printed on a box is an area.
How much tile do I need for common room sizes?
Tiles needed for common floor sizes with 1/8 in grout joints, computed with the same formula as the calculator. There is no waste allowance in these figures, so add yours before buying.
| Floor size | Square feet | 12 × 12 in tiles | 12 × 24 in tiles | 24 × 24 in tiles |
|---|---|---|---|---|
| 5 × 8 ft | 40 | 40 | 20 | 10 |
| 10 × 10 ft | 100 | 98 | 50 | 25 |
| 12 × 10 ft | 120 | 118 | 60 | 30 |
| 12 × 12 ft | 144 | 142 | 71 | 36 |
| 12 × 14 ft | 168 | 165 | 83 | 42 |
| 15 × 20 ft | 300 | 294 | 148 | 75 |
Quick answers: how many tiles for common floors
Each answer is computed with the same formula as the calculator, using its default settings unless the question says otherwise.
How many 12x24 tiles for an 8x10 bathroom?
An 8 × 10 ft bathroom is 80 sq ft, or 88 sq ft with a 10% allowance, and takes 44 tiles of 12 × 24 in with 1/8 in grout joints.
How many 24x24 tiles for a 12x16 room?
A 12 × 16 ft room is 192 sq ft, or 211.2 sq ft with a 10% allowance, and takes 53 tiles of 24 × 24 in with 1/8 in grout joints.
How many 6x24 tiles for a 5x10 bathroom floor?
A 5 × 10 ft bathroom floor is 50 sq ft, or 55 sq ft with a 10% allowance, and takes 54 tiles of 6 × 24 in with 1/8 in grout joints.
How many 18x18 tiles do I need for a 15x15 room?
A 15 × 15 ft room is 225 sq ft, or 247.5 sq ft with a 10% allowance, and takes 109 tiles of 18 × 18 in with 1/8 in grout joints.
How much tile do I need for a 12x15 kitchen?
A 12 × 15 ft kitchen is 180 sq ft, or 198 sq ft with a 10% allowance, and takes 194 tiles of 12 × 12 in with 1/8 in grout joints.
How many 12x12 tiles do I need for 100 square feet?
Covering 100 sq ft, or 110 sq ft with a 10% allowance, takes 108 tiles of 12 × 12 in with 1/8 in grout joints.
How many 3x6 subway tiles for 30 square feet?
Covering 30 sq ft, or 33 sq ft with a 10% allowance, takes 249 tiles of 3 × 6 in with 1/8 in grout joints.
How many 4x4 tiles for a 20 sq ft backsplash?
Covering 20 sq ft, or 22 sq ft with a 10% allowance, takes 187 tiles of 4 × 4 in with 1/8 in grout joints.
How many boxes of tile or flooring to buy
The default 12 × 10 ft floor needs 130 tiles of 12 × 12 in with a 10% allowance. To turn that into boxes, enter the tiles per box printed on the box you are buying.
- Buy enough from the same lot or batch, since color can vary between production runs.
- Keep a few spare tiles for future repairs.
- Thinset, grout, and spacers are separate purchases. Their labels state how much area each covers.
Flooring calculator: planks, vinyl, and laminate
Plank flooring is usually sold by the box, with the coverage per box printed on it. Choose Coverage per box, enter that figure, and set the grout joint to 0. The calculator divides the area plus allowance by the box coverage and rounds up to whole boxes.
Wall tile and backsplashes
Measure the wall height and length you are tiling, subtract windows or cabinets, and enter the result as a total area. For an L-shaped or broken-up wall, add the pieces in the square footage calculator first.
Tips for measuring and ordering tile
- Measure the room at several points. Walls are rarely perfectly square, so use the largest measurements.
- Subtract fixed items such as kitchen islands or tubs only if no tile goes under them.
- Large-format tiles and patterns such as herringbone produce more offcuts, so raise the allowance. See tile layout patterns for offset and grout joint rules by pattern.
- For rooms that are not rectangles, find the area first with the square footage calculator, or see measuring irregular areas.
Tile calculator FAQ
How do I calculate how many tiles I need?
Find the area to tile, add a waste allowance, and divide by the area of one tile including one grout joint each way. Round up to whole tiles, then divide by the tiles per box and round up to whole boxes.
How many 12x12 tiles do I need for a 10x12 room?
A 12 × 10 ft room is 120 sq ft. With 1/8 in grout joints and a 10% allowance, it takes 130 tiles of 12 × 12 in. Without an allowance it would be about 118.
How much extra tile should I buy?
There is no universal figure. Straight layouts in simple rooms waste less; diagonal or patterned layouts, large tiles, and rooms with many corners waste more. Set the allowance to match your layout, and keep spares for repairs.
Does grout spacing change the number of tiles?
Slightly. Each tile plus its joint covers a bit more area than the tile alone, so wider joints mean a few fewer tiles. Set the joint to 0 for a more cautious count.
How many tiles are in a box?
It varies by product and tile size. Use the count or coverage printed on the box or product page. The calculator does not assume a box size.
Can I use this as a flooring calculator for laminate or vinyl planks?
Yes. Choose coverage per box, enter the square footage printed on the box, set the grout joint to 0, and read the number of boxes.
Can I enter tile sizes in centimeters?
Yes. Switch the tile unit to cm, enter the grout joint in millimeters, and the room in meters if you prefer. The calculator converts everything before dividing.
Related calculators and guides
Calculators
- Square Footage Calculator — Total area in square feet, square meters, square yards, and acres from rectangles, triangles, circles, and trapezoids, minus cut-outs.
- Drywall Calculator — Drywall sheet count for walls and ceilings from room dimensions or total area, minus openings, by sheet size.
- Paint Calculator — Gallons or liters of paint for your walls and number of coats, using the coverage printed on your paint's label.
Guides
- Tile Layout Patterns and How They Change Your Order — Common tile patterns, the industry offset and grout joint rules for large tile, centering a layout, and overage by pattern.
- How to Measure an Irregular Area — Split odd shapes into rectangles, triangles, circles, and trapezoids, then average width and depth.
Sources
- NIST Guide to the SI, Appendix B.9: Factors for units listed by kind of quantity — National Institute of Standards and Technology. Used for: 1 ft = 0.3048 m (exact); 1 in = 2.54 cm (exact). Checked 2026-10-03.