FORMULA
How the calculation works
Rectangle: A = L × W · Circle: A = πr² · Triangle: A = b × h ÷ 2
Choose a shape and unit, enter its dimensions and quantity, then optionally add a cost per square foot.
CONSTRUCTION & MEASUREMENT / FREE ONLINE TOOL
Square Footage Calculator
Calculate area in square feet, square meters, square yards and acres for rectangles, circles and triangles.
INPUT
LOCAL CALCULATIONEnter your values
RESULT
FORMULA v1.0.0Your calculation
ResultReady
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EXAMPLE
Worked example
A 20 ft × 15 ft rectangle covers 300 ft², which is approximately 27.87 m².
Formula reviewed July 30, 2026 · Version 1.0.0
FAQ
Frequently asked questions
Is this calculator free?
Yes. It is free to use and does not require an account.
Are my values uploaded?
No. This calculation runs locally in your browser.
SOURCE & LIMITS
Methodology
Standard plane geometry formulas; 1 ft² = 0.09290304 m².
Results are estimates. Confirm measurements, product specifications and professional requirements before making critical decisions.