Tile Calculator
Use your own numbers after reviewing the formula and worked example.
Quick answer
Tile count equals adjusted project area divided by the area covered by one tile, rounded up.
Formula or method
Keep units, percentages and time periods consistent. The formula is useful as a transparent check on the calculator result and helps explain why changing one input changes the answer.
Step-by-step
- Calculate project area.
- Convert tile dimensions to compatible units.
- Find area per tile.
- Add waste, divide and round up.
Worked example
A 150-sq-ft room using 12×12-inch tiles with 10% waste needs coverage for 165 sq ft, or at least 165 one-sq-ft tiles before box rounding.
How to interpret the result
Diagonal layouts, patterns and many cuts can increase waste.
When the answer is used for a purchase, loan, payroll decision, construction order, school grade, health estimate or other real-world choice, verify the assumptions that matter in that context. Accurate arithmetic still depends on accurate inputs.
Common mistakes
- Mixing inches and square feet.
- Rounding tile count down.
- Ignoring pattern waste.
Frequently asked questions
How much waste should I add?
It depends on layout and installer guidance.
Do grout lines change the estimate?
Basic estimates use nominal tile dimensions; exact layout can vary.
Should extra matching tile be kept?
Many projects keep extra for breakage and repairs.