Tile calculator
How many tiles and boxes you need for a floor or wall, with waste.
About this calculator
How many tiles do I need? This tile calculator works it out from the size of the floor or wall and the size of your tiles.
Add the grout gap, a waste allowance and the number of tiles per box to know exactly what to buy.
How it works
The area is length × width. Each tile covers its size plus the grout gap. The area divided by the tile coverage gives the tile count, rounded up, plus your waste allowance.
Last reviewed:
Worked example
- Measure in: Feet and inches
- Area length: 12 ft
- Area width: 10 ft
- Tile length: 12 in
- Tile width: 12 in
- Grout gap: 0.125 in
- Extra for waste and cuts: 10%
Tiles needed: 130 (including extra for waste)
Common questions
How much extra tile should I buy?
About 10% for simple layouts, and 15% or more for diagonal patterns, small rooms with many cuts, or large-format tiles.
How do I measure a room with an odd shape?
Split it into rectangles, work out each one, and add the tile counts together.
Should I keep spare tiles?
Yes. Colours vary between production batches, so a few spares from the same batch make future repairs match.
The story behind it
Where the idea came from: Glazed tiles go back thousands of years, from ancient Egypt to the blue and white azulejos of Portugal and Spain.
Tiles last for centuries because fired clay resists water and wear. The maths of tiling hasn't changed: cover the area, allow for cuts, and buy enough from one batch.
Why you can trust this calculator
- It runs in your browser. Nothing you type into it is sent anywhere.
- The method is explained on this page, so you can check it yourself.
- Free to use, with no sign-up.
- Results are estimates, so please double-check anything important.
- Spotted a mistake? Tell us and we'll look into it.
After 15 years as a mathematics educator, I built CalculStore to give students, teachers, professionals and anyone working with numbers simple, reliable tools.
Meet the founder