Free tile calculator — tile, thinset and grout
Work out how many tiles you need, how many boxes to buy, and how much thinset and grout goes with them. Handles floors and walls, adjusts waste for your layout pattern, and recommends the right trowel for your tile size. No signup, nothing to download.
Most tile calculators stop at the tile count. Setting material is where jobs actually get held up, so this one figures that too.
How to use it
1. Pick floor or wall and enter the two dimensions in feet.
2. Deduct openings. Doorways, windows, a tub surround, the footprint of cabinets — subtract them in square feet so you aren't buying tile for space you'll never cover.
3. Choose your tile size and layout. The pattern matters more than people expect. A straight lay wastes about 10%; diagonal runs 15%; herringbone and chevron can hit 18% or more, because nearly every perimeter tile becomes a cut.
4. Set your grout joint and tile thickness. Both feed the grout calculation — a wider joint or a thicker tile means noticeably more grout.
Waste is not optional
Ten per cent is the floor, not a safety margin you can skip. You will break tiles, you will mis-cut, and you want spares left over for repairs years later when the run is discontinued. Add more than the default when the room is small (proportionally more perimeter to cut), when the walls are out of square, or when the tile has a directional pattern you have to align.
Buy the same lot number
Tile colour varies between production runs, sometimes dramatically. Buy all of it in one order and check that the lot or batch number matches on every box before you open them. A mid-job top-up from a different lot is one of the most common ways a good install ends up looking wrong.
Trowel size drives your thinset
Thinset coverage depends almost entirely on the notch size, which in turn depends on your tile. As a rule: up to 8 inches use a 1/4" × 1/4" square notch; 8 to 16 inches use 1/4" × 3/8"; over 16 inches use 1/2" × 1/2". The calculator picks the right one and adjusts coverage automatically. On anything large format, back-butter every tile as well — you are aiming for full contact, not just ridges.
Turn it into a quote
Hit Copy list to put the whole materials list on your clipboard, ready to paste into an estimate. Add your labour, price it with the profit margin calculator, and send it with the estimate generator.
Also useful: our fence calculator and state-by-state rate data for what tile setters and carpenters earn in your state.
FAQ
How do I calculate how many tiles I need?
Work out the area in square feet, subtract any openings, then add your waste percentage. Divide that by the coverage of a single tile, which is the tile's width times its height in inches divided by 144. A 12" × 24" tile covers exactly 2 square feet, so 120 square feet plus 10% waste needs 66 tiles.
How much waste should I add for tile?
Ten per cent for a straight or stacked layout, about 12% for offset or running bond, 15% for diagonal, and 18% or more for herringbone and chevron. Add extra on top for small rooms, out-of-square walls, or any tile with a pattern that has to line up.
How much thinset do I need per square foot?
It depends on your trowel, not the area alone. A 50 lb bag covers roughly 95 square feet with a 1/4" × 1/4" notch, about 70 square feet with 1/4" × 3/8", and around 45 square feet with 1/2" × 1/2". Coverage drops if the substrate is uneven, because you use more mortar filling low spots.
How much grout do I need?
Grout is driven by joint volume, which comes from tile size, joint width and tile thickness. Small tiles with wide joints use far more grout per square foot than large tiles with tight joints — a mosaic can need several times what a large-format floor needs over the same area. This calculator uses the standard joint-volume formula, but coverage varies by brand, so check the chart printed on your bag.
What size trowel should I use for 12x24 tile?
Use a 1/2" × 1/2" square-notch trowel for 12" × 24" tile, and back-butter each piece. Anything over about 15 inches on its long side counts as large format, which means you want a mortar rated for it and you are aiming for full coverage underneath — not just combed ridges with voids between them.
Does this work for a shower or backsplash?
Yes. Switch to Wall mode, enter the width and height of the area, and deduct any openings such as a niche or window. For a shower with three walls, add the three wall areas together and enter the total. Tile thickness defaults thinner in Wall mode because wall tile usually is.
Is this tile calculator free?
Yes, completely free. No account, no email, no download. It runs in your browser and we never see your numbers.