Square Footage Calculator
Calculate area in square feet, square yards, square meters, and acres for rectangles, squares, triangles, and circles.
Formula
Rectangle: L × W. Triangle: ½ × base × height. Circle: π × r² (or π × (d/2)² from diameter).
Assumptions
- All dimensions are converted to feet internally before area calculation.
Limitations
- Does not estimate material cost or coverage depth.
- Irregular shapes require breaking into simpler shapes.
Worked example
12 ft × 15 ft rectangle
Area = 180 square feet = 20 square yards.
Frequently asked questions
Should I enter radius or diameter for a circle?
This calculator uses diameter by default. The formula converts diameter to radius internally: area = π × (diameter ÷ 2)².
Last reviewed: 2026-07-23
Category: Construction & Materials
Results are provided for informational purposes only and may not reflect real-world policies, fees, or individual circumstances.
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