Area calculator

Find the area of plane shapes in eleven modes with mixed input units and a selectable output unit.

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Use the example values or enter your own measurements.
Calculate, then copy the result or download the available details.

Example

Input

A rectangle 4 m by 3 m

Expected result

12 m²

Try it

Good to know

The calculation runs in your browser. Use consistent units in fields with no explicit unit.

Calculation method

Dimensions convert to meters before calculation. The three-side triangle uses Heron’s formula. A sector uses half the squared radius times its angle in radians.

A_{\mathrm{rectangle}}=lw,\qquad A_{\mathrm{sector}}=\tfrac12 r^2\theta

A_{\mathrm{triangle}}=\sqrt{s(s-a)(s-b)(s-c)},\quad s=\tfrac12(a+b+c)

Calculation mode

Rectangle

Length
Length unit
Width
Width unit
Area unit

Square

Edge length
Edge length unit
Area unit

Triangle · three sides

First side
First side unit
Second side
Second side unit
Third side
Third side unit
Area unit

Triangle · base and height

First parallel side
First parallel side unit
Perpendicular height
Perpendicular height unit
Area unit

Trapezoid

First parallel side
First parallel side unit
Second parallel side
Second parallel side unit
Perpendicular height
Perpendicular height unit
Area unit

Circle

Radius
Radius unit
Area unit

Circular sector

Radius
Radius unit
Central angle
Angle unit · Degrees / Radians
Area unit

Ellipse

First semi-axis
First semi-axis unit
Second semi-axis
Second semi-axis unit
Area unit

Parallelogram

First parallel side
First parallel side unit
Perpendicular height
Perpendicular height unit
Area unit

Annulus

Outer radius
Outer radius unit
Inner radius
Inner radius unit
Area unit

Regular polygon

Edge length
Edge length unit
Number of sides
Area unit