Tile calculator
How many tiles to buy?
Measure the floor or wall, pick a tile, and get the number of tiles and boxes to order, with spares for cuts and breakages. The preview shows roughly how the layout will fall.
Nothing you enter is saved or sent.
Buy every box from the same batch if you can; shade varies between production runs. The count ignores grout width, which makes it slightly generous.
Free tool from Ready Home Family
How the number is worked out
Area of the room divided by the area of one tile gives the bare count. Then add spares: tiles get cut at the edges, a few break, and you want some left for repairs years later.
How much extra to allow
| Layout | Spare | Why |
|---|---|---|
| Straight grid | 10% | Cuts only along the walls |
| Brick or offset | 10% | Half tiles at alternate row ends are mostly reusable |
| Diagonal or herringbone | 15% | Every edge tile is cut at an angle, with more waste |
| Awkward rooms | 15% or more | Alcoves, pipes and angled walls eat tiles |
Measuring tips
- Split odd shapes into rectangles, work each out and add them together.
- Measure at the widest points. Walls are rarely square; use the larger figure.
- Take out what will not be tiled: a bath, a kitchen island, fitted units that stay put.
- For walls, use height × width and subtract windows and doors.
Before you order
Check the box: coverage per box is printed on it and is more reliable than counting tiles, because nominal sizes are rounded. Keep one unopened box if the shop allows returns, and keep a few loose tiles in the loft either way. A cracked tile in five years is a ten-minute job if you have a match, and a retiling job if you do not.
Questions people ask
How do I calculate how many tiles I need?
Divide the area of the room by the area of one tile, then add 10% for cuts and breakages, or 15% for diagonal layouts. A 120 sq ft floor with 2 sq ft tiles needs 60 tiles, or 66 with spares.
How much extra tile should I buy?
Ten percent for a straight or brick layout in a simple room, and 15% for diagonal or herringbone patterns or rooms with many corners.
How many 12 × 24 tiles do I need for 100 square feet?
Each 12 × 24 inch tile covers 2 square feet, so 50 tiles for 100 square feet, or 55 with a 10% allowance.
One job measured. The rest of the house?
RoomMend: Safer Home Plans is an iPhone app for walking through a home room by room and keeping a list of what to fix. Its listing says it plans a reminder to look again 30 days after a fix is ticked done, and keeps before, after and recheck photos in each room's history.
Get RoomMend on the App StoreFree includes walkthroughs, rooms and notes, fix lists, reminders, rechecks and room PDFs; RoomMend Plus is an optional one-time purchase. It is not a home inspection, safety certification or medical tool.
Honest Little Apps publishes both RoomMend and this page. This is a separate browser tool and does not sync with the app. App details checked November 10, 2026.
On a computer? Open it on your iPhone
