The Square Footage Calculator measures the area of a space in square feet — essential for real estate, flooring, painting, landscaping, and construction projects. It supports rectangular, triangular, circular, and irregular shapes, and converts between square feet, square meters, square yards, and acres.
How the Formula Works
Rectangle: Area = Length × Width. Triangle: Area = ½ × Base × Height. Circle: Area = π × r². Irregular shapes: Break into rectangles and triangles, calculate each, and sum.
How to Use This Calculator
Select the shape of the area you're measuring
Enter the dimensions in feet, inches, or meters
View the area in square feet and other units
For irregular spaces, break into multiple shapes and add them together
Tips & Best Practices
Always add 10% extra for waste when ordering flooring, tile, or other materials
Measure each room at the widest points — walls are rarely perfectly straight
For L-shaped rooms, divide into two rectangles, calculate each, and add together
1 acre = 43,560 square feet (roughly the size of a football field without end zones)
Important Limitations
Assumes flat surfaces — sloped or vaulted areas require different calculations
Wall square footage for painting differs from floor square footage
Irregular shapes require approximation by breaking into simpler shapes