Tile Calculator
Find out exactly how many tiles and boxes you need to cover an area, with a waste allowance built in.
Example
A 4 m x 3 m floor is 12 m². Each 30 cm x 30 cm tile covers 0.09 m², so you need 134 tiles (12 ÷ 0.09 = 133.3, rounded up). Adding 10% waste gives 147 tiles, which is 15 boxes at 10 tiles per box.
How it works
Tiles = ceil(area ÷ tile area × (1 + waste%)). The tool divides the surface area by one tile's area, adds a waste percentage for cuts and breakage, rounds up to whole tiles, then divides by tiles-per-box and rounds up for boxes.
Good to know
The Tile Calculator works out how many individual tiles and full boxes you need to cover a floor or wall, based on the dimensions of your space, the size of a single tile, and a waste allowance. It's aimed at DIY renovators, homeowners planning a kitchen or bathroom, and tradespeople who want a quick second check before ordering. You enter the area's width and length, one tile's width and height, a waste percentage, and how many tiles come in a box; everything is calculated instantly in your browser.
Reach for it at the quoting and shopping stage, before you commit to a purchase. Because tile is sold in sealed boxes and dye lots can vary between production runs, buying slightly too few is far more painful than buying a little extra. Running the numbers first tells you the realistic box count so you can match lots in a single order and keep a spare box for future repairs.
Read the results from the bottom up. "Base tiles (no waste)" is the bare minimum to cover the area assuming zero cuts, "Extra for waste" is the cushion added by your waste percentage, and "Tiles needed" is the sum, rounded up to whole tiles. "Boxes to buy" then rounds that figure up to complete boxes, so the headline box count is usually a few tiles more than you strictly need. The "Area to cover" line confirms the tool read your room dimensions correctly.
One practical caveat: the calculator treats your space as one clean rectangle, so for L-shaped rooms or areas with islands and alcoves, split the space into rectangles and add the results, and remember it does not subtract doorways, niches, or fixtures. Switch the unit toggle to Imperial if you are working in feet and inches, and bump the waste figure up for large-format tiles or diagonal and herringbone patterns where offcuts pile up quickly.
Frequently asked questions
How much waste percentage should I add for tiles?
Add about 10% for a standard straight (grid) layout. Increase it to 15-20% for diagonal or herringbone patterns, irregularly shaped rooms, or large-format tiles, since these create more offcuts and breakage.
Why does the calculator round up the number of tiles and boxes?
You cannot buy a fraction of a tile or a box, so the result is always rounded up to the next whole unit. This ensures you have enough to finish the job and a few spares for future repairs.
Is my data uploaded anywhere?
No — this calculator runs entirely in your browser. Your inputs never leave your device, and it works offline once loaded.
Is this calculator free?
Yes, completely free with no sign-up and no limits.
People also ask
How do I calculate how many tiles I need for a room?
Divide the area you want to cover by the area of a single tile, then round up to a whole number of tiles. For a 12 m² floor with 30 cm x 30 cm tiles (0.09 m² each), that is 12 ÷ 0.09 = 134 tiles before any waste allowance.
Does this tile calculator work for walls as well as floors?
Yes. The math is identical for any flat rectangular surface, so you can enter the height and width of a wall instead of the length and width of a floor. Just measure each wall separately and total the results if you are tiling several.
How many tiles are usually in a box?
It varies by tile size and brand, commonly ranging from about 5 to 15 tiles per box, often listed as a square-meter or square-foot coverage on the packaging. Check the box label or product page and enter that exact number for an accurate box count.
Should I include grout lines when measuring tiles?
This calculator uses the nominal tile dimensions and does not separately model grout joints, which slightly increases the area each tile covers. The built-in waste allowance generally absorbs that small difference for typical joint widths.
How do I figure tiles for an L-shaped or irregular room?
Split the space into simple rectangles, calculate each one separately, and add the tile counts together. The calculator assumes a single rectangle, so combining sections by hand keeps the estimate accurate for non-rectangular layouts.
Why should I keep leftover tiles after a project?
Tiles from the same production run share a dye lot, and exact colors can shift between batches over time. Keeping a few spares or a leftover box means future repairs blend in instead of standing out as a mismatched replacement.
Does the calculator account for doorways or fixtures I won't tile?
No. It calculates the full rectangular area you enter and does not subtract doorways, cabinets, niches, or fixtures. If a large portion will not be tiled, measure and subtract that area before entering your dimensions.
How accurate is an online tile estimate compared to a professional measure?
It gives a solid planning estimate based on clean rectangular dimensions and your waste figure, but it cannot see room quirks, layout patterns, or cut complexity. For large or expensive jobs, confirm the final quantity with the tile supplier or installer before ordering.
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