Square Footage Calculator
Calculate combined square footage and square meters for simple rectangular areas.
Calculate your materials
Your estimate
Enter your measurements and select Calculate estimate to see the results.
Estimates are for planning only; verify product specifications and local requirements.
How this square footage calculator works
Square footage is the starting point for many flooring, tile, paint and material estimates. This calculator multiplies a rectangular area by the number of matching spaces and allows a measured area to be subtracted. Break complex rooms into rectangles instead of estimating from an irregular outline.
The calculation
Net area in square feet = (length × width × number of matching areas) − subtracted square feet. Square meters = square feet × 0.09290304.
Worked example
Two 12 ft × 10 ft rooms total 240 sq ft. Subtracting a 20 sq ft area gives 220 sq ft, approximately 20.44 sq m.
Before buying materials
- Measure wall-to-wall dimensions consistently.
- Use separate calculations for L-shaped rooms, then add the areas.
- Keep a sketch to avoid counting the same space twice.
Frequently asked questions
Can this calculate an L-shaped room?
Split the shape into rectangles, calculate each area separately, then add them.
Are square feet the same as linear feet?
No. Square feet measure area; linear feet measure a single distance.
Does this calculate waste?
No. Add a project-appropriate waste allowance in the specific material calculator.