Tile Calculator
Calculate how many tiles, boxes, grout, and thinset you need for floors and walls. Includes waste factor and cost estimates.
How to Use This Calculator
Getting the right tile count prevents costly delays and ensures you have matching tiles for repairs. Here's how to calculate accurately:
- Measure your room dimensions in feet. For irregular rooms, break them into rectangles and add the areas.
- Select your tile size from common options or enter custom dimensions in inches.
- Enter your grout joint width (1/8" is standard for most floor tiles).
- Adjust the waste factor: 10% for simple layouts, 15-20% for diagonal or complex patterns.
- Enter pricing to estimate total material cost.
Why This Matters
Tile installation is a significant investment, and running short mid-project can be disastrous. Tiles from different production lots often have color variations, so it's essential to order enough from the same lot. Overestimating wastes money, but underestimating costs even more due to project delays and mismatched tiles.
- Calculate exact tile quantities including waste for cuts
- Know how many boxes to order from the same lot
- Estimate grout and thinset requirements
- Budget accurately with cost estimates
- Keep spare tiles for future repairs
Worked Examples
Standard Bathroom Floor
A 8' × 10' bathroom with 12×12 tiles and 10% waste factor.
Calculation: 80 sq ft ÷ 1 sq ft/tile = 80 tiles + 10% waste = 88 tiles
Result: Order 9 boxes (10 tiles per box). Keep extras for repairs.
Large Kitchen with Diagonal Layout
A 15' × 20' kitchen using 18×18 tiles laid diagonally.
Calculation: 300 sq ft ÷ 2.25 sq ft/tile = 134 tiles + 15% waste = 154 tiles
Result: Order 16 boxes. Diagonal layouts create more cuts and waste.
Subway Tile Backsplash
A 3' × 15' backsplash area using 3×6 subway tiles.
Calculation: 45 sq ft ÷ 0.125 sq ft/tile = 360 tiles + 10% waste = 396 tiles
Result: Order 40 boxes (10 per box). Small tiles require many more pieces.
Common Mistakes to Avoid
- Not buying all tiles from the same lot - color variations between lots can be noticeable.
- Underestimating waste factor - cuts, breakage, and defects all add up.
- Forgetting to subtract for cabinets but not adding back for cuts - you still need tiles for the cuts.
- Not keeping spare tiles - finding matching tiles years later for repairs is often impossible.
- Measuring in inches instead of feet - double-check your units before ordering.