How to use this square footage calculator
Enter the requested values above and select Calculate. The result updates immediately on the page, so you can change one value and compare different scenarios without leaving the calculator.
Formula and method
Square feet = length × width.
Example
A 20 ft by 15 ft room contains 300 square feet.
What this calculator is useful for
Calculate rectangular area in square feet from length and width measurements in feet. It is designed for quick estimates and everyday problem solving. When a calculation affects a contract, tax filing, medical decision or other high-stakes situation, verify the result with the appropriate professional or authoritative source.
Frequently asked questions
What does the Square Footage Calculator calculate?
Calculate rectangular area in square feet from length and width measurements in feet.
How does the calculation work?
Square feet = length × width.
Is this calculator free?
Yes. ERICH Calculators is free to use and no account is required.