Trade Math · Square Feet
Calculating total square feet
Area shows up whenever you're ordering flooring, figuring tile, or sizing a roof patch. The formulas are short; the mistakes are where points go. Here's the rectangle, the triangle, the circle, and how to handle the composite shapes that make up real rooms.
Cheat sheet
- Rectangle: Area = L × W
- Triangle: Area = (1/2) × base × height
- Circle: Area = π × r² (π ≈ 3.14)
- Composite shapes: split into sub-rectangles and add, OR start from the bounding rectangle and subtract what's missing.
- Unit conversion: 1 sq ft = 144 sq in (12 inches × 12 inches).
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