Tile Calculator
Each tile's real coverage includes the grout line around it, not just the tile's own dimensions — skipping that undercounts how many you'll actually need.
Free tile calculator that accounts for grout spacing — enter your room and tile dimensions and get the exact tile count (and box count, if you know tiles-per-box), not just room area divided by tile area.
How it works
- Enter your room's length and width, and your tile's length and width
- Set the grout spacing and a waste factor
- See the exact tile count needed, and box count if you enter tiles per box
Frequently asked questions
Why does grout spacing matter for the count?
Each tile's real footprint on the floor includes the grout line around it, not just the tile's own size — a 12" tile with 1/8" grout actually claims about 12.125" × 12.125" of floor. Ignoring that undercounts how many tiles you need, especially over a large room.
What waste factor should I use?
10% is a common default for a straightforward rectangular room. Diagonal layouts, rooms with lots of cuts, or a first-time DIY installation often warrant 15% or more.
Related tools
From the blog
Update history
- 2026-09-01 Launched: tile calculator that factors in grout spacing for accurate tile counts, with an optional tiles-per-box conversion. Entirely client-side.