
How to Measure Stairs for Carpet
Width x ((Run+Rise+Nose) x Number of stairs) = Area

For a straight staircase:
- Measure the rise and run. Add them together. Include an inch or two extra to wrap around the nose.
- Rise: height of the step.
- Run: length of the step.
- Multiply that by the number of stairs.
- Divide by 12 and round up to get the number of feet.
- Measure the width of the stairs and round up to the nearest foot.
- Multiply the width from step 4 by the length from step 3.
- Add in any landings you have. Multiply the width and length of the landing. Add that number.
If you have an irregular, circular or unique setup, it’s best to hire a professional.
For a stairwell with 13 stairs and one landing:
- 7+7+2 = 16 inches. 7 inches for each rise and run plus two inches for the nose and overage
- 16 inches x 13 stairs = 208 inches.
- 208 inches/12 = 17.33 (round up) = 18 feet.
- 4 x 18 = 72 square feet. Width is 4 feet.
- 4 x 4 = 16 square feet for the 4-foot by 4-foot landing.
- 72+16 = 88 total square feet.