Carpet Calculator Formula
Understand the math behind the carpet calculator. Each variable explained with a worked example.
Formulas Used
Area (Square Feet)
square_feet = area_sqftArea (Square Yards)
square_yards = area_sqydSq Yards (with waste)
sqyd_with_waste = area_sqyd * (1 + waste_percent / 100)Estimated Material Cost
estimated_cost = area_sqyd * (1 + waste_percent / 100) * price_per_sqydVariables
| Variable | Description | Default |
|---|---|---|
room_length | Room Length(feet) | 15 |
room_width | Room Width(feet) | 12 |
waste_percent | Waste/Overage(%) | 10 |
price_per_sqyd | Price per Sq Yard(USD) | 30 |
area_sqft | Derived value= room_length * room_width | calculated |
area_sqyd | Derived value= room_length * room_width / 9 | calculated |
How It Works
How to Calculate Carpet Needed
Formula
Square Yards = (Length × Width) / 9
Carpet is sold by the square yard in the United States. One square yard equals 9 square feet (3 ft × 3 ft). Add 10% for waste due to seams, pattern matching, and room irregularities. Carpet typically comes in 12-foot wide rolls.
Worked Example
A room 15 ft by 12 ft at $30 per square yard with 10% waste.
room_length = 15room_width = 12waste_percent = 10price_per_sqyd = 30
- 01Area = 15 × 12 = 180 sq ft
- 02Square yards = 180 / 9 = 20.00 sq yd
- 03With 10% waste = 20 × 1.10 = 22.00 sq yd
- 04Cost = 22.00 × $30 = $660.00
Ready to run the numbers?
Open Carpet Calculator