Square Footage Calculator
Calculate square footage for any rectangular area from length and width — the starting number behind flooring, paint, sod, and per-square-foot material orders.
How this calculator works
Square footage is the most fundamental number in any building or yard project — it’s the input every flooring, paint, sod, and drywall estimate starts from. This calculator simply multiplies length by width to give you the area, with no density, weight, or coverage-rate conversion applied.
Formula: Square feet = Length (ft) × Width (ft).
Worked example
A 20 ft × 15 ft room or patio:
- Square feet: 20 × 15 = 300.00 sq ft
- The price field defaults to $0.00, so cost reads $0.00 unless you enter your own per-square-foot rate for materials or labor.
Coverage reference
| Area | Square feet |
|---|---|
| 10 ft × 7.5 ft | 75.00 sq ft |
| 20 ft × 15 ft | 300.00 sq ft |
| 40 ft × 30 ft | 1,200.00 sq ft |
How to measure your area
Measure length and width in feet along the straightest, longest lines of the space — for a room, that’s wall to wall; for a yard, that’s the outer boundary of the section you’re covering. For anything other than a simple rectangle, break the footprint into smaller rectangles, calculate each one separately, and add the totals together for the true combined square footage.
Frequently asked questions
How do I find square footage for a room or yard that isn't a perfect rectangle?
Split the space into rectangles — an L-shaped room becomes two rectangles, a yard with a bump-out becomes a main rectangle plus a smaller one — run this calculator for each piece, and add the results together. For a rough circular area, use radius squared × 3.14159 instead of length × width.
What's the difference between square footage and square yards?
Square yards are square feet divided by 9, since one square yard is a 3 ft × 3 ft square. Carpet and some sod is priced per square yard, while flooring, paint, and drywall are almost always priced per square foot — this calculator gives you the square-foot figure directly.
Why does the price field default to $0.00?
Square footage alone doesn't have a universal price — a square foot of paint coverage, flooring, or lawn each cost something different per unit. Leave the price at $0 to get a pure area number, or enter your own per-square-foot rate (materials, labor, or both) if you have one to price out the job.
Should I round up my square footage before ordering material?
It depends on the material. This tool gives you the exact rectangular area; add a buffer yourself for cuts and waste — 5-10% for flooring or tile, more for patterns with a lot of angles or obstacles. Material-specific calculators like the tile or flooring calculator build that waste percentage in for you.
Estimates only. Verify quantities with your supplier before purchasing.