Carpet Calculator – How Much Carpet and Padding
This carpet calculator tells you how much carpet and padding to buy for one room or a whole house. Enter each room's length and width in feet, choose a 12 or 15 foot roll width, add a waste allowance and the price per square yard. The calculator works out the total floor area, the linear feet of roll needed with seams considered, the square yards to order and the estimated cost including padding. Carpet is sold by the square yard in the US, so results are shown in both square feet and square yards. Always confirm measurements and seam layout with your installer before ordering.
Carpet Calculator
Estimate carpet, padding and cost for one or more rooms, with roll width and waste.
How to use the Carpet Calculator
- Enter the length and width in feet for each room, and add more rooms with the add button.
- Choose the roll width, 12 feet or 15 feet.
- Set the waste percentage and the price per square yard.
- Add the padding price if you need padding.
- Read the total area, square yards to order and estimated cost.
How it works
Area = length × width for each room. Roll length for a room = the number of strips needed across the roll width × the length of each strip, using the best direction. Square yards = square feet ÷ 9, plus the waste allowance. The order is the larger of the area estimate and the roll-length estimate.
Features
- Multiple rooms
- 12 or 15 foot roll widths
- Seam-aware roll length
- Waste allowance
- Carpet and padding cost
- Copy and print
Frequently asked questions
How do I calculate how much carpet I need?
Multiply the length by the width of each room in feet to get square feet, add 10% for waste and divide by 9 to get square yards.
How much extra carpet should I buy?
Plan for 10% extra on simple rooms and 15% or more for rooms with patterns, many angles or stairs.
Why is the roll length bigger than the room area?
Carpet comes in fixed 12 or 15 foot widths, so you pay for the full width of every length you cut, even if the room is narrower.
How many square feet are in a square yard?
One square yard is 9 square feet, which is a 3 foot by 3 foot square.
Do I need padding under carpet?
Yes. Padding adds comfort, lasts longer than bare carpet and usually matches the floor area in square yards.