Area Calculator

Calculate the area of a rectangle, circle, or triangle from dimensions.

Geometry formulas for common shapes, expressed in square units.

Your inputs stay on your device

Calculate area

live result

Shape

First value

Width

Area

square units

Enter dimensions or values only; results are mathematical estimates and do not replace construction, engineering, or academic requirements.

Context & Reference

For basic rectangle, circle, and triangle measurements.

calculator guide

Uses dimensions for rectangle area, circle area, or half base times height.

Use this calculator with your own values, then review the clearly labelled result and copy it when you need it elsewhere.

Area is expressed in the square unit implied by your inputs.

Find a circle area from radius 3.

All required dimensions must be positive.

This calculator runs locally in this browser. All required dimensions must be positive.

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Continue with a closely related task, calculation, conversion, or local text tool.

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