Donaldson R F Carpet Calculator
Enter your room size and roll width to see how much carpet to order, which way to run it, and what you will pay.
How much carpet to buy
Carpet is sold from a roll, usually 4 m or 5 m wide in the UK (12 ft or 15 ft in the US), and you pay for the full width of the length you buy. The calculator tries running the carpet in both directions, counts the strips needed, adds the trimming allowance at each end and rounds up to a whole pattern repeat, then picks the option that uses the least carpet. Fewer joins usually means a better-looking floor, so check where the seams would fall.
This is an estimate for one rectangular room. Alcoves, doorways, stairs and pile direction can change the amount, and fitters often want to measure and advise on where to place seams. Add extra if you might need a repair piece later. Related: square footage calculator.