Stair Carpet Calculator
Calculate the exact amount of carpet needed for your stairs. Enter number of steps, riser height, tread depth, and stair width for total carpet length, area, and cost with charts.
About This Calculator
Our Stair Carpet Calculator helps homeowners, contractors, interior designers, and DIY enthusiasts estimate the exact amount of carpet required for any staircase project. Whether you are carpeting a straight staircase, a flight with a landing, or installing a stair runner, this tool provides accurate measurements for carpet length, width, total area, and material cost.
The calculation works by measuring each step individually: add the riser height (vertical rise of each step) to the tread depth (horizontal run), then multiply by the total number of steps. Any landing area is added separately, and a waste allowance (typically 10 percent) is applied to account for cuts, trimming, nosing overhangs, pattern matching, and installation adjustments. The carpet cost is computed based on your chosen material price per unit area.
Regional Notes
India: Carpet is typically sold per square foot. Standard staircase dimensions use risers around 15-18 cm and treads around 25-30 cm. Prices range from ₹80-350 per sq ft. Popular materials include nylon, polyester, and wool blends.
US: Carpet is sold per square foot. Standard residential stairs have 7-inch risers and 11-inch treads. Carpet and installation cost $3.50-12.00 per step, with total projects averaging $250-600 for a 13-step staircase.
UK: Carpet is sold per square meter. Standard stairs have 18-20 cm risers and 25-28 cm treads. Supply and fitting costs £15-50 per square meter, with a typical 12-step staircase costing £200-500.
Frequently Asked Questions
How much carpet do I need for my stairs?
To calculate stair carpet, measure the riser height (vertical) and tread depth (horizontal) of one step, add them together, multiply by the number of steps, then add any landing depth. Include 10 percent extra for waste and trimming. The stair width determines the carpet roll width needed.
How do I measure stairs for carpet?
Measure the riser height (vertical part of each step), tread depth (horizontal part), and stair width (side to side). Count the number of steps. For a staircase with 13 steps, each with 7-inch risers and 11-inch treads, the total carpet length is 13 × (7 + 11) = 234 inches plus landing area.
What is the standard waste percentage for stair carpet?
A 10 percent waste allowance is standard for stair carpet installation. This accounts for cuts around nosing overhangs, trimming at walls, pattern matching, and miscalculations. For patterned carpets or complex staircases with landings and turns, consider increasing waste to 15 percent.
Can I use a stair runner instead of full carpet?
Yes, a stair runner is a popular alternative that covers only the center portion of the stairs, leaving exposed wood or flooring on the sides. To calculate stair runner carpet, follow the same length formula but reduce the width to your desired runner width, typically 27 to 36 inches for standard stairs.
How much does it cost to carpet stairs in the US?
In the US, stair carpet installation costs between $3.50 and $12.00 per step for materials, plus labor averaging $5 to $15 per step. A 13-step staircase with mid-range carpet typically costs $250 to $600 total. Carpet quality, padding, and stair complexity affect the final price.
How much does stair carpet cost in India?
In India, stair carpet prices range from ₹80 to ₹350 per square foot depending on material quality. Basic nylon or polyester carpets cost ₹80-150/sq ft, while wool or premium options range ₹200-350/sq ft. Installation labor adds ₹15-30 per sq ft. A standard 15-step staircase costs approximately ₹12,000 to ₹35,000 total.
How much does stair carpet cost in the UK?
In the UK, stair carpet costs £15 to £50 per square meter for materials with installation adding another £8 to £20 per square meter. A typical 12-step straight staircase costs £200 to £500 for supply and fitting. Underlay adds approximately £3-8 per square meter.
Do I need to account for nosing overhang when measuring?
Yes, stair nosing overhang typically adds 1 to 2.5 cm (0.5 to 1 inch) to each step's carpet requirement. When carpeting, the material wraps around the nosing and tucks underneath. Our calculator uses the combined riser plus tread measurement which naturally accommodates standard overhangs.