Flooring / Tiling Calculator
Work out how many tiles or boards you need, and the total cost.
How this is calculated
Room area is length times width. Adding your waste percentage gives the area to actually buy for, which is then divided by each tile or board's area and rounded up to a whole unit — you can't buy a fraction of a tile.
The right waste percentage depends heavily on layout: a simple square layout in a rectangular room can often get away with 5–10%, while diagonal or herringbone patterns commonly need 15% or more due to the extra edge cutting involved. Flooring projects often go hand in hand with other room-renovation estimates — see the Paint Coverage Calculator for wall paint needs, and the Concrete Volume Calculator if you're pouring a new subfloor or slab before laying the finish flooring.
Frequently asked questions
- Why add a waste percentage?
- Cutting tiles or boards to fit around edges, corners and obstacles always produces some offcuts you can't use elsewhere. 10% is a common default for a simple rectangular room; more complex layouts or diagonal patterns often need 15% or more.
- Does this account for the layout pattern?
- No — this gives a straightforward area-based estimate. Patterns like herringbone or diagonal laying typically increase waste beyond the percentage you enter, so consider a higher waste allowance for those.
- Can I use this in my own app?
- Yes — every calculator on Stupidly Clever has a matching REST API and MCP tool that runs the same underlying logic.
- How is the area calculated?
- Room area is simply length times width. Your waste percentage is added on top to get the total area to actually purchase, which is then divided by each tile or board's individual area and rounded up to a whole unit.
- What wastage should I use for diagonal tile laying?
- Diagonal layouts typically require significantly more cutting at the room's edges than a standard square layout, so 15–20% waste is a more realistic allowance than the standard 10% default — complex patterns like herringbone can need even more.
- What size tiles are most efficient to lay?
- Larger tiles generally mean fewer grout lines and faster installation, but produce more waste on irregular room shapes since each cut wastes a larger piece. Smaller tiles waste less material on odd angles and cuts but take longer to install and have more grout lines. Neither is universally "more efficient" — it depends on the room shape and installation time value.
- What is the difference between m² of tiles needed and boxes to buy?
- The calculated area (including waste) tells you the minimum material needed, but tiles and flooring are usually sold in fixed-size boxes covering a set area — you'll typically need to round up to the next whole box, which can mean buying slightly more than the calculated figure alone would suggest.