Flooring Calculator

How much flooring to buy

Buying flooring is more than length × width. You need extra material for cuts, mistakes, and future repairs, and flooring is sold by the box — so the real question is "how many boxes?" This calculator works out your floor area, adds a waste allowance, and rounds up to whole boxes.

Choosing a waste allowance

• 5–10% for a simple square or rectangular room laid straight.
• 15% for diagonal layouts, lots of doorways, or angled walls.
• 20% for herringbone and other patterned installs.

FAQ

Should I keep the leftovers?

Yes — hold onto at least one full box. Dye lots change between production runs, so a future repair with fresh stock may not match. Leftovers from the same batch are the perfect spare.

How much waste should I add?

Use about 5–10% for a plain square or rectangular room laid straight, 15% for diagonal layouts or rooms with many doorways and angled walls, and up to 20% for herringbone and other patterned installs. More cuts mean more offcuts, so busier layouts need a bigger allowance.

Why does it round up to whole boxes?

Flooring is sold by the box, not by the square foot or meter, so a partial box isn't an option. The calculator converts your area-plus-waste into the number of full boxes you actually need to buy.

Can I enter the room in meters or feet?

Yes. The calculator works in either unit system, so enter your room dimensions and the box coverage in whichever units your flooring is sold in and it handles the rest.

Does it stay private, and is it free?

Yes to both. The calculation runs entirely in your browser so your measurements never leave your device, and the tool is free with no sign-up and works on mobile.