Carpet Calculator
Estimate carpet square footage and square yards, including waste for seams and pattern match.
What you need
25
Square yards needed — Rounded up, waste allowance included.
- Area to cover
- 200.0 sq ft
- Area including waste allowance
- 220.0 sq ft
Estimates for planning. Confirm quantities with your supplier before ordering — see the assumptions below for the figures used.
How to use the carpet calculator
Carpet is quoted per square foot or per square yard, and comes off a 12 foot wide roll — which means a 13 foot room wastes a lot. Enter your room dimensions for area, square yards and a realistic material allowance.
What this calculator assumes
Every estimate depends on figures that vary by supplier and conditions. These are the ones used here, so you can sanity-check the result against your own quote.
- Coverage per square yard is taken from your entry above — always check the actual packaging, because it varies by product.
- A 10% waste allowance is applied by default. Increase it for diagonal layouts, busy patterns or rooms with lots of corners.
- Square yards are rounded up to whole units.
- Broadloom carpet comes on 12 foot wide rolls (occasionally 15 ft). Any room dimension between 12 and 24 feet forces a seam and significant waste that a percentage allowance only approximates.
- One square yard is 9 square feet. Installers usually quote in square yards even where retail pricing is per square foot.
- Padding, tack strip, transitions and installation are not included. Padding is sold to the same area as the carpet.
Frequently asked questions
How do I convert square feet to square yards for carpet?
Divide the square footage by 9. A 12 by 15 foot room is 180 square feet, which is 20 square yards. Add your waste allowance before converting, not after, or you will be a yard or two short.
Why does carpet waste so much material?
Because it comes on a 12 foot roll. A room 13 feet wide needs a second piece seamed on for that extra foot, and the offcut is usually unusable. Rooms that are exactly 12 feet or under in one direction are dramatically cheaper to carpet.
Do I need carpet padding?
Yes, for broadloom carpet in a living space. It carries most of the wear, adds insulation and makes a mid-range carpet feel far better underfoot. Buy the same area as the carpet. Carpet tiles and some commercial products are designed to go down without it.
How much extra should I buy?
The default here is 10%. Buying a little extra from the same batch is cheap insurance — colours and lots shift between production runs, so a mid-project top-up rarely matches. Keep the offcuts for future repairs.
How do I handle an L-shaped or irregular room?
Split it into rectangles, work out each one separately and add the results. Measure at the widest point of each section and ignore small alcoves unless you are covering them too.
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