Area Calculator
Calculate the area of a rectangle, triangle, circle, trapezoid or parallelogram.
Area
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Perimeter / circumference
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Results update as you type.
About this calculator
An area calculator finds how much surface a 2D shape covers. Pick the shape and enter its dimensions: a rectangle is length × width, a triangle is ½ × base × height, a circle is π × radius², a trapezoid is ½ × (base₁ + base₂) × height, and a parallelogram is base × height. Only the fields the chosen shape needs are used.
Frequently asked questions
How do you find the area of a triangle?
Area = ½ × base × height, using the perpendicular height. A triangle with base 6 and height 4 has area ½ × 6 × 4 = 12.
What is the area of a circle?
Area = π × radius². A circle of radius 5 has area π × 25 ≈ 78.54.
Results are estimates for general guidance only, not financial, medical or tax advice.