Tile Calculator
Estimate a rectangular tile layout from the actual tile face dimensions, planned grout-joint width, box quantity, and project cutting allowance.
What does the tile calculator calculate?
This tile calculator divides the installation into repeating tile-and-joint modules, rounds rows and columns up, and then adds waste to the resulting piece count. It also converts pieces into full boxes. Complex patterns, borders, niches, and tiles from different dye lots should be estimated separately.
Tile grid and box formula
Rows and columns use the actual tile plus grout-joint module. Each direction rounds up before waste because a partial final row or column still requires cut pieces.
How to measure for an accurate estimate
- Measure each flat floor or wall plane separately and subtract openings only when no cut tiles are required around them.
- Use actual tile dimensions, which may differ from the nominal size printed in a product name.
- Enter the joint width specified by the tile manufacturer and compatible installation standard.
- Count pieces per unopened box directly from the label; do not assume every box covers the same area.
Twelve-by-ten-foot tile floor
A 12-by-10-foot floor receives 12-inch tiles, 1/8-inch joints, 15 tiles per box, and 10% waste.
The grid requires 120 tiles; adding waste gives 132 tiles, so 9 full boxes are needed.Before you purchase material
- Purchase tile from one shade and caliber lot, then verify all cartons before installation begins.
- Use a larger allowance for diagonal, offset, herringbone, heavily veined, or color-selective layouts.
- Dry-lay representative rows so narrow cuts can be balanced at opposite walls.
- Keep labeled spare tiles for repairs because future production lots may not match.
Common questions
How many extra tiles should I order?
Ten percent is a common starting allowance for a simple straight layout. Consider 15% or more for diagonal patterns, many corners, fragile tile, strong shade selection, or future repairs. The installer and tile manufacturer should confirm the final order quantity.
Does grout-joint width change the tile count?
Yes. A grout joint adds space between tile faces, so the repeating layout module is slightly larger than the tile itself. The effect may remove a row or column on a large surface, although edge cuts and layout balancing still require judgment.
Should I subtract cabinets from kitchen floor tile?
Subtract permanently covered footprints only when tile will not run beneath them and the installation plan allows that approach. Include toe-kick recesses, appliance openings, and exposed floor. Confirm cabinet sequencing and flooring requirements before reducing the order.
Can I combine floor and wall tile quantities?
Calculate each plane separately, especially when orientation, pattern, cuts, or tile sizes differ. You may combine the final box order only when every surface uses the identical product, shade lot, caliber, and acceptable waste allowance.
Sources and reference standards
- Tile Council of North AmericaIndustry installation resources for ceramic and stone tile assemblies.