Home / Interior / TileTile Calculator Enter area and tile size to get tile count and boxes, with waste for cuts.
Your estimate
See products Results update as you type. Round up when ordering.
Based on 15 sq ft per box. Box coverage varies by tile — check the carton.
Formula checked against manufacturer specs Rounded up to whole units Runs in your browser
Tile formula Tiles = floor area ÷ area of one tile, plus waste. Tile area in sq ft = tile length (in) × width (in) ÷ 144. A 12 × 12 in tile is exactly 1 sq ft.
How much waste to add Straight lay, simple room: 10% Diagonal or herringbone: 15–20% Large-format tiles or many obstacles: 15%+ Keep a few spare tiles from the same dye lot for future repairs—later batches often differ slightly in shade.
Grout joints This estimate ignores grout width, which slightly reduces the tile count—another reason the waste allowance is conservative.
✓ Formula reviewed and tested · Updated Oct 2026
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FAQ How accurate is the tile calculator? It uses the standard formula shown on this page and rounds bags, boxes and pieces up to whole units. Product sizes vary by brand, so confirm with the label or your supplier before you buy.
Should I buy extra material? Yes. A 5–10% allowance covers cuts, spills and uneven surfaces; running short mid-job usually costs more than a few leftovers.
Is this calculator free? Yes. Every PorchMath calculator is free, needs no account and runs entirely in your browser.