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Area and Perimeter Calculator

Work out the area and perimeter of ten plane shapes, with the formula and a scale diagram shown alongside.

Works in BrowserInstant
Shape
Area
Diagram
All Properties
Units are whatever you enter — if lengths are in cm, area is in cm² and perimeter in cm. Ellipse perimeter uses Ramanujan's approximation, which is accurate to better than 1 part in 10⁷ for most shapes.