✓ Effortless Math · Free Tool

Area & Perimeter Calculator

Pick a shape, enter its dimensions, and instantly get the area and perimeter (or circumference) — with the formula used, a to-scale diagram, and full step-by-step working.

Supports:  rectangle, square, triangle, circle, parallelogram, and trapezoid.
Shape
Length (l) Width (w)

Tip: all lengths must be positive. Decimals are fine.

Results

Area
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—
Perimeter
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Area formula
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Perimeter formula
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Diagram

Shape outlineDimension labels

Step-by-step