Carpet Calculator
Work out how much carpet a room needs — in square yards for pricing, and in linear feet off the roll for ordering — including seams, pattern matching and cutting waste.
Carpet is the one flooring sold two ways at once: priced by the square yard, but cut from a roll of fixed width. A room can need two strips — and a seam — even when the area looks modest. This calculator handles both numbers.
It works for broadloom (roll) carpet. For carpet tiles, calculate the area with the tile square foot calculator instead, using the tile size.
Your results
Enter your measurements and press Calculate.
Quantities are rounded up to whole tiles, planks, boxes or bags, after the wastage allowance. Cost appears only when you enter a price.
Formula
All lengths are converted to a single unit before the calculation: 1 ft = 0.3048 m, 1 in = 25.4 mm, 1 ft² = 0.09290304 m², 1 yd² = 9 ft². Material quantities are rounded up — you cannot buy part of a tile, plank or bag.
How to use this calculator
- Measure the room length and width in feet or metres.
- Enter the roll width your carpet comes on — usually 12 ft or 4 m.
- Set wastage: 10% for plain carpet, 15% for a pattern that must match at the seam.
- Add the price per square yard if you want a cost estimate.
Worked example
| Room | 12 ft long × 15 ft wide = 180 ft² |
|---|---|
| In square yards | 180 ÷ 9 = 20 yd² |
| Carpet with 10% wastage | 20 × 1.10 = 22 yd² |
| Strips off a 12 ft roll | ⌈15 ÷ 12⌉ = 2 strips |
| Linear length | 2 × 12 ft × 1.10 = 26.4 ft |
| Cost at $25 per yd² | 22 × $25 = $550 |
Check it by hand: every step above uses the formula in the box. If your numbers match the example inputs but the calculator gives a different answer, please report it via the contact page.
Frequently asked questions
Why is carpet sold by the square yard?
Carpet has traditionally been priced per square yard (9 sq ft). One square yard of carpet covers 9 square feet of floor. This calculator shows both, so a US quote and a metric measurement are easy to compare.
What is a strip, and why does it matter?
Carpet comes off a roll of fixed width, so a room wider than the roll needs two or more strips joined by a seam. The strip count tells you how much roll length to order — a room 13 ft wide on a 12 ft roll needs 2 strips, even if the area alone looks small.
How much extra do I need for patterned carpet?
Allow 15% instead of 10%. The pattern must line up across the seam, which wastes the offcut at the end of each strip. Plain carpet with no pattern to match needs only the 10% cutting allowance.
Should I include the area under wardrobes?
Measure wall to wall. Carpet runs under fitted wardrobes only if they are installed after the carpet; freestanding furniture sits on top of the carpet, so its footprint still counts.
Related calculators
Estimates only. Results are for planning. Measure twice, confirm box coverage and tile sizes on the packaging you buy, and follow the manufacturer's instructions. See the disclaimer.