How to use the square footage calculator
- Choose your unit: feet, inches, yards, meters or centimeters.
- Enter the length and width of each area. Use + Add area for more rooms, or to split an L-shaped room into rectangles.
- Set an allowance for waste and, optionally, a price per square foot to estimate the cost.
Square footage formula
Area (sq ft) = Length (ft) × Width (ft)
Material needed = Area × (1 + Waste % ÷ 100)
Example: a 12 × 10 ft bedroom (120 sq ft) and a 15 × 13 ft living room (195 sq ft) total 315 sq ft. With 10% extra for waste, buy 346.5 sq ft. At $4 per sq ft, flooring costs about $1,386.
Typical material costs (US, materials only)
| Material | Typical price per sq ft |
|---|---|
| Carpet | $2 – $6 |
| Laminate | $1.50 – $5 |
| Luxury vinyl plank | $2 – $7 |
| Ceramic / porcelain tile | $1 – $15 |
| Hardwood | $5 – $15 |
| Sod | $0.35 – $0.85 |
Prices vary widely by region, brand and quality. Installation usually costs extra, often $2–$10 per sq ft depending on the material.
Measuring tips
- Measure wall to wall at floor level, and round up to the next inch.
- Split odd shapes into rectangles and add them up. Subtract areas that won't be covered, like a kitchen island.
- Include closets and doorways if the flooring continues into them.
- Buy all your material at once so colors and batches match.
Frequently asked questions
How do I calculate square footage?
For a rectangular area, multiply the length by the width, both in feet. A room 12 ft long and 10 ft wide is 120 square feet. For an L-shaped room, split it into rectangles, calculate each one and add them together — that's what the rows above are for.
How much extra flooring should I buy?
Add about 5–10% for waste from cuts and mistakes. Use 10–15% for diagonal or herringbone layouts, patterned tile or rooms with lots of corners. It's also smart to keep a few spare pieces for future repairs.
How do I convert square feet to square meters?
Multiply square feet by 0.0929 to get square meters, or divide square meters by 0.0929 (multiply by 10.764) to get square feet. 100 sq ft is about 9.29 m².
How do I measure a room with inches?
Convert inches to decimal feet by dividing by 12. For example, 10 ft 6 in is 10.5 ft, and 12 ft 3 in is 12.25 ft. Or choose "inches" as the unit and enter everything in inches.