Square Footage Calculator
Add Multiple Rooms
Area Conversions
Related Calculators
Understanding Square Footage
Common Uses
Real Estate
- Home/apartment size
- Price per square foot
- Lot size calculations
- Property comparisons
Home Improvement
- Flooring materials
- Paint coverage
- Carpet/tile needs
- Sod/grass seed
Formulas by Shape
| Shape | Formula |
|---|---|
| Rectangle | Length x Width |
| Triangle | (Base x Height) / 2 |
| Circle | Pi x Radius^2 |
| Trapezoid | ((Base1 + Base2) / 2) x Height |
Measuring Tips
For irregular rooms, divide the space into rectangles and triangles, calculate each area separately, then add them together. Always measure in feet and inches for accuracy, then convert inches to decimal feet (divide inches by 12).
Frequently Asked Questions
How do I calculate square footage of a room?
Multiply length by width in feet: Area = Length x Width. For a 12x15 foot room: 12 x 15 = 180 square feet. For irregular rooms, divide into rectangles, calculate each, and add them together.
How do I convert square feet to square yards?
Divide square feet by 9 (since 1 yard = 3 feet, 1 sq yard = 9 sq ft). For example, 180 sq ft / 9 = 20 square yards. This is useful for carpet, which is often priced per square yard.
How many square feet is an acre?
One acre equals 43,560 square feet. A half-acre lot is 21,780 sq ft. To visualize, an acre is about 90% of a football field (excluding end zones).
How do I include feet and inches in my calculation?
Convert inches to decimal feet by dividing by 12. For 10 feet 6 inches: 10 + (6/12) = 10.5 feet. Then multiply as usual. A 10'6" x 12'3" room = 10.5 x 12.25 = 128.625 sq ft.