Area Calculator
Calculate area of any common geometry shape. Select a shape, enter dimensions, and the calculator updates instantly. A diagram appears on the right to help you understand the measurements visually.
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Area formulas
- Rectangle: A = width × height
- Square: A = side²
- Circle: A = π × r²
- Triangle: A = ½ × base × height or Heron’s formula
- Parallelogram: A = base × height
- Trapezoid: A = ½ × (a + b) × height
- Rhombus: A = ½ × d₁ × d₂
- Ellipse: A = π × a × b
- Sector: A = ½ × r² × θ
- Regular Polygon: A = (n × s²) / (4 × tan(π/n))
Examples
Rectangle 5 m × 3 m → Area = 15 m²
Circle radius 2 m → Area = π × 4 = 12.566 m²
Input rules
- All inputs must be positive numbers.
- Length units convert automatically to area units.
- Triangle allows base-height OR 3 sides.
- Sector angle supports degrees or radians.
FAQ
Yes — enter dimensions in one unit and choose area unit separately.
The calculator shows a visual guide for the selected shape.