Carpet calculator

How to use it

Enter the room's length and width in feet, choose the roll width (12 ft is by far the most common), and set how much extra to allow on each strip for trimming at the walls. The calculator lays the carpet both ways, picks the one that needs less, and tells you how many strips, how much roll and how many seams that takes.

Why carpet takes more than the room's area

Carpet is cut from a roll of fixed width, so you pay for full widths. A 14 × 16 ft room is 224 sq ft (about 25 sq yd), but on a 12 ft roll it needs two strips, and the second strip is mostly offcut. That's why the amount to buy is often well above the room's area.

How it's calculated

1. Strips = the side running across the roll ÷ roll width, rounded up.
2. Each strip = the other side + the trim allowance.
3. Square yards = strips × roll width × strip length ÷ 9.
4. Steps 1 to 3 are worked out both ways, and the smaller amount is shown.

On a 12 ft roll with 6 in trim per strip:

Room	Room area	Carpet to buy	Seams
10 × 12 ft	13.3 sq yd	14 sq yd	None
12 × 14 ft	18.7 sq yd	19.3 sq yd	None
14 × 16 ft	24.9 sq yd	38.7 sq yd	1
15 × 20 ft	33.3 sq yd	41.3 sq yd	1
20 × 24 ft	53.3 sq yd	54.7 sq yd	1

Tips

• Rooms 12 ft wide or less fit in one strip of 12 ft carpet with no seam, which is cheaper and looks better.
• Installers can use offcuts to fill small areas like closets and doorways, so a professional quote may come in a little under this figure.
• Pile direction: all strips must run the same way, or the seams show. That's why this calculator doesn't turn offcuts sideways.
• Pad is bought for the room's area, shown under "Room area".

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