Area Calculator
Find the area of a rectangle, circle or triangle from its dimensions.
Quick answer: enter your details below and click Calculate — your result appears instantly, right here in your browser. Nothing you enter is uploaded or stored.
A
Calculators
Enter your details below.
How to use
- Choose a shape.
- Enter the dimensions that shape needs.
- Calculate to see its area.
About this tool
Pick a shape and enter only the measurements that shape needs. A rectangle uses length times width, a circle uses pi times the radius squared, and a triangle uses half times base times height. The tool checks that you gave the dimensions for the shape you picked before calculating.
Frequently asked questions
Do I need to fill in every box?
No. Only the dimensions for your chosen shape are used, so leave the others blank.
What units is the answer in?
Square units matching whatever unit you measured in: centimetres give square centimetres, metres give square metres, and so on.