Square Footage Calculator
Calculate area in square feet for any room shape. Supports rectangle, circle, triangle, L-shape, and trapezoid with metric conversion and visual comparisons.
How It Works
Understand how area is calculated for different shapes and units.
Shape Formulas
Rectangle: length × width. Circle: π × radius². Triangle: 0.5 × base × height. Trapezoid: 0.5 × (base1 + base2) × height. L-Shape: divide into two rectangles and add. Use the Combined Total tab to sum multiple room areas.
Unit Conversions
1 square foot = 0.0929 square meters. 1 square yard = 9 square feet. 1 acre = 43,560 square feet. 1 hectare = 107,639 square feet. All conversions happen automatically when you calculate any shape.
Visual Comparisons
The comparison bars show your area relative to common references. A tennis court is 2,808 sq ft, a standard parking space is 162 sq ft, and a king bed is 42 sq ft. This gives you an intuitive sense of scale.
Frequently Asked Questions
Common questions about measuring and calculating square footage.
For a rectangular room, multiply the length by the width. For example, a room that measures 12 feet by 14 feet is 168 square feet. For irregular rooms, divide the space into smaller rectangles, calculate each area, and add them together. Circular rooms use the formula π × radius² (radius is half the diameter).
One square meter equals 10.764 square feet. To convert square feet to square meters, divide by 10.764. To convert square meters to square feet, multiply by 10.764. For rough estimates, use 10: one square meter is approximately 10 square feet. Real estate listings in the US use square feet, while most other countries use square meters.
To calculate total house square footage, measure each room individually (length × width), including closets, hallways, and bathrooms. Add all room areas together. For multi-story homes, calculate each floor separately and sum them. Do not include unfinished basements, attics, or garages in the calculation. Use the calculator's Combined Total feature to add multiple room measurements.