Geometry · Area
Area Calculator
Find the area of a square, rectangle, triangle, or circle.
Area Calculator
Choose a shape, enter its measurements, then select Calculate.
How these calculations work
A square's area is its side squared. A rectangle's area is length × width. A triangle's area is half its base times its height. A circle's area is π times its radius squared.
Examples
A square with a 5-unit side has an area of 25. A 30×20 rectangle has an area of 600. A triangle with a 30-unit base and 45-unit height has an area of 675. A circle with a 5-unit radius has an area of about 78.54.
About these formulas
These are standard geometry formulas — no external source citation is needed for them.
Related tools
More calculators are on the way — browse everything planned on the Home page.
Frequently asked questions
What units does the result use?
Whatever unit you enter your measurements in — the result is in that same unit, squared. For example, entering measurements in meters gives an area in square meters.
Why does the calculator say my input is invalid?
A required field is empty or not a number, or a measurement is zero or negative — a length, base, height, or radius must be a positive number.
Area Solution
Area
Result will appear here.
Calculation steps