⬛ Area Calculator
Choose a shape and enter its measurements. The answer is in square units of whatever unit you used.
Area
How the Area Calculator works
Each shape has its own formula. Make sure all measurements use the same unit.
Rectangle: L × W · Triangle: ½ × base × height · Circle: π × r²
Trapezoid: ½ × (a + b) × h · Parallelogram: base × height · Ellipse: π × a × b
Step-by-step calculation
- 1Choose the shape.
- 2Enter the measurements.
- 3Apply the shape's area formula.
Worked example
A 12 × 8 rectangle has an area of 96 square units. A circle with radius 5 has an area of π × 25 ≈ 78.54.
Area Calculator examples
| a | Area |
|---|---|
| 6 | 48 square units |
| 9 | 72 square units |
| 12 | 96 square units |
| 15 | 120 square units |
| 18 | 144 square units |
Other inputs kept at the calculator's default values. Results calculated by this calculator.
Why use an Area Calculator?
Find area for homework, flooring, painting and land.
Important factors that can affect your results
- Same units for all sides.
- Radius vs diameter.
- Irregular shapes need splitting.
Frequently asked questions
How do I find area in square feet from inches?
Divide square inches by 144.
Radius or diameter?
The circle formula uses the radius — half the diameter.
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Last reviewed November 2026 · How we build and check our tools · Report a problem