Tile Coverage Calculator

Direct answer

Divide the measured floor area by the face area of one tile, add the waste allowance you choose, then round up to a whole tile. NIST lists 144 square inches in one square foot; this calculator uses that conversion only to put room and tile measurements on the same area basis.

Variables and formula

• Room dimensions: measured rectangular floor length and width in feet.
• Tile dimensions: face length and width in inches.
• Waste allowance: the extra percentage you decide to include for cuts, breakage, pattern and spare tiles.

Tiles to buy = ceiling(Room area / Tile face area * (1 + Waste allowance))

Reproducible example

A 12 ft by 10 ft floor is 120 sq ft. With 12 in by 12 in tiles (1 sq ft each) and 10% allowance, ceiling(120 / 1 * 1.10) = 132 tiles.

Interpretation

The whole-tile result is a purchasing starting point. Check the planned layout, border pieces and package quantity before ordering, and keep spare tiles from the same production batch when practical.

Assumptions and limitations

• The floor and tile face are rectangular measurements.
• Grout-joint width and irregular exclusions are not calculated separately.
• The waste allowance is a user decision, not a universal installation recommendation.

Common mistakes

• Dividing square feet directly by tile dimensions in inches.
• Rounding down before adding the allowance.
• Treating a simple rectangle as a complete cut layout.

Assumptions

• The floor is rectangular and the tile dimensions describe the usable tile face.
• The selected allowance accounts for cuts, breakage, pattern direction and future spares.
• Grout joints, border pieces and irregular exclusions are not calculated separately.

Sources and methodology

CalcMotive publishes the formula and assumptions so you can decide whether the estimate fits your use case. See our methodology standards.

• Handbook 133 Appendix E: General Tables of Units; National Institute of Standards and Technology; accessed Aug 3, 2026