Tile Calculator: How Much Tile Do You Need (And Why You Should Buy Extra)?

Tile calculations seem simple: measure the area, divide by tile size, buy that many tiles. This approach leads to running out mid-project and discovering your tile is discontinued, backordered, or from a different dye lot.

The Basic Calculation

Area to tile (sq ft) ÷ tile area (sq ft per tile) = tiles needed before waste

A 10×12 bathroom floor (120 sq ft) with 12×12-inch tiles (1 sq ft each):

120 ÷ 1 = 120 tiles before waste

Waste Factors by Pattern

Straight lay (tiles parallel to walls): Add 10%

120 tiles × 1.10 = 132 tiles

Offset/brick pattern: Add 10–15%

Staggered joints require cutting at edges; slightly more waste.

Diagonal (45° angle): Add 15–20%

Diagonal cuts at every wall generate significantly more waste.

Herringbone or complex pattern: Add 20–25%

Complex patterns require precise cuts and careful planning.

Why Extra Tiles Are Essential

Current order: Buy the calculated amount plus the waste factor.

Future repairs: Buy 5–10% extra beyond that and store it. Tile lines are discontinued constantly. Matching a repair tile 3 years later — same color, same texture, same dye lot — is often impossible. Tiles from different manufacturing runs (dye lots) can vary noticeably in color and texture even with identical product numbers.

The extra tiles you store cost $30–50 today. The custom-order tile to match your floor in 5 years (if available at all) costs $150–300. The math is clear.

Grout Calculation

Grout quantity depends on tile size, joint width, and tile thickness. Our calculator handles this automatically — input your tile dimensions and joint size for the grout estimate.

[Calculate tile needed →](https://doesitaddup.com)

This article is for informational purposes only. See our disclaimer.