Square Footage Calculator
Enter each shape with one consistent unit. The calculator converts every area to a common base, adds them, and then displays the total in your chosen unit.
How to use this calculator
Choose a shape for the first area.
Enter its measured dimensions and add more areas if needed.
Read the total in square feet, square meters, or another available area unit.
Formula
Rectangle: A = length × width. Triangle: A = base × height ÷ 2. Circle: A = π × radius². Total area is the sum of all shapes.
Worked example
A 12 ft × 10 ft rectangle plus an 8 ft × 6 ft rectangle has an area of 120 + 48 = 168 ft².
Assumptions and limits
- Dimensions describe flat geometric shapes.
- All dimensions are converted before areas are added.
- No waste allowance is applied by default.
Sources
Related calculators
Frequently asked questions
How do I calculate an irregular space?
Split it into rectangles, triangles, or circles, add each part, and omit any cutout as a separate negative measurement outside this tool.
Can I use metric and US customary units in the Square Footage Calculator?
Yes. Unit changes convert the same canonical measurement; they do not reinterpret or round your original value.
When does the calculator round?
The calculation keeps full precision internally and rounds only the displayed result. Whole packages are rounded up at the final step.
Last updated · formula-v1 · content-2026-08-14 · Trusty Calculator Editorial Team