🪜 Stair Carpet Calculator
Calculate carpet needed for stair installation
How to Use This Calculator
Enter Number of Steps
Input the total number of steps in your staircase. Count all steps from bottom to top landing.
Specify Stair Dimensions
Select tread depth (standard is 11 inches), tread width (standard is 36 inches), and riser height (standard is 7.5 inches). These dimensions determine the carpet area per step.
Add Landings (if applicable)
If your stairs have landings (top or intermediate), select "Yes" and enter the total landing area in square feet. This adds to the total carpet needed.
Calculate and Order
Click "Calculate Stair Carpet" to see carpet needed in square yards (with 10% waste), total area in square feet, and linear feet. Order carpet by square yards.
Formula
Tread Area per Step = Tread Depth (ft) × Tread Width (ft)
Riser Area per Step = Riser Height (ft) × Tread Width (ft)
Total Area per Step = Tread Area + Riser Area
Total Stairs Area = Total Area per Step × Number of Steps
Total Area (sq yd) = (Total Stairs Area + Landing Area) ÷ 9
Example 1: Standard Stairs (13 steps, 11" tread, 36" width, 7.5" riser, no landings)
Step 1: Convert to feet: Tread = 11/12 = 0.917 ft, Width = 36/12 = 3 ft, Riser = 7.5/12 = 0.625 ft
Step 2: Tread area per step: 0.917 × 3 = 2.75 sq ft
Step 3: Riser area per step: 0.625 × 3 = 1.875 sq ft
Step 4: Total area per step: 2.75 + 1.875 = 4.625 sq ft
Step 5: Total stairs area: 4.625 × 13 = 60.125 sq ft
Step 6: Convert to square yards: 60.125 ÷ 9 = 6.68 sq yd
Step 7: Add waste: 6.68 × 1.10 = 7.35 sq yd (with 10% waste)
Example 2: Stairs with Landing (16 steps, 12" tread, 42" width, 7.5" riser, 30 sq ft landing)
Step 1: Total area per step: (12/12 × 42/12) + (7.5/12 × 42/12) = 5.68 sq ft
Step 2: Total stairs area: 5.68 × 16 = 90.88 sq ft
Step 3: Add landing: 90.88 + 30 = 120.88 sq ft
Step 4: Convert to square yards: 120.88 ÷ 9 = 13.43 sq yd
About Stair Carpet Calculator
The Stair Carpet Calculator is an essential tool for homeowners, contractors, and carpet installers who need to accurately determine how much carpet is required for stair installation. This calculator eliminates guesswork by providing precise carpet area calculations based on number of steps, tread dimensions, riser height, and landings, helping you order the right amount of carpet without waste or shortages.
When to Use This Calculator
- Stair Carpet Installation: Calculate carpet needed for new stair carpet installation
- Carpet Replacement: Determine carpet quantities for stair carpet replacement projects
- Budget Planning: Calculate carpet costs by determining exact quantities needed
- Contractor Estimates: Quick reference for contractors bidding stair carpet projects
- Material Ordering: Order carpet accurately based on stair dimensions
Why Use Our Calculator?
- ✅ Accurate Area Calculation: Precise calculations prevent over-ordering or running short
- ✅ Square Yards: Shows carpet area in square yards (carpet is sold by square yard)
- ✅ Tread and Riser: Includes both tread (horizontal) and riser (vertical) areas
- ✅ Landing Support: Includes landing areas if applicable
- ✅ Linear Feet: Shows linear feet for runner installation
- ✅ Time Savings: Instant calculations eliminate manual math and measurements
Common Applications
Stair Carpet Installation: Homeowners and contractors installing stair carpet use this calculator to order the correct quantity of carpet. Carpet is sold by square yard, so converting from square feet is essential.
Carpet Replacement: Contractors and homeowners planning stair carpet replacement use this tool to estimate carpet quantities needed. Stair carpet replacement typically requires careful measurements for accurate ordering.
Budget Planning: Homeowners and contractors use this calculator to calculate carpet quantities for budget planning and cost estimation, ensuring accurate project budgets.
Tips for Best Results
- Tread Dimensions: Standard is 11 inches depth and 36 inches width; measure actual dimensions
- Riser Height: Standard is 7-7.5 inches; measure actual riser height
- Add Waste: Always add 10% extra for waste, cuts at angles, and mistakes
- Order by Square Yards: Carpet is typically sold by square yard, not square foot
- Landings: Include landing areas separately if carpeting landings
- Pattern Matching: Add extra for pattern matching if carpet has patterns
Frequently Asked Questions
How many square yards of carpet do I need for stairs?
Carpet needed depends on number of steps and stair dimensions. For example, 13 standard steps (11" tread, 36" width, 7.5" riser) need approximately 7.35 square yards of carpet (with 10% waste). Use the calculator with your specific dimensions for accurate estimates.
Do I need to include risers in carpet calculations?
Yes! If you're carpeting both treads and risers, include riser area in calculations. The calculator includes both tread (horizontal) and riser (vertical) areas. If only carpeting treads, use tread area only, but most stair carpet installations include risers.
Should I add extra carpet for waste?
Yes! Always add 10% extra for waste, cuts at angles, corners, and mistakes during installation. Stairs have many angles and cuts, so waste can be significant. The calculator includes 10% waste automatically.
How is carpet sold - by square foot or square yard?
Carpet is typically sold by square yard in the United States. This calculator converts from square feet to square yards for easy ordering. Always check with your carpet supplier for their pricing unit.
What if I only want a runner instead of full carpet?
For runner installation, use the linear feet calculation. Runners are sold by linear foot or linear yard. The calculator shows linear feet needed for runner installation. Runners typically cover only the center of stairs.
Do I need to add extra for pattern matching?
Yes! If your carpet has patterns, add extra for pattern matching. Pattern matching can add 10-20% additional waste depending on pattern size and alignment requirements. Add this to the calculated amount.