Area Calculator

Calculate area of rectangles, circles, triangles, and more.

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Unit:
$
Area Formula Reference
Rectangle A = length × width
Circle A = π × r²
Triangle A = ½ × base × height
Trapezoid A = ½ × (b1 + b2) × height
Ellipse A = π × a × b

Frequently Asked Questions

How do I calculate the area of a rectangle or room?

Area = Length × Width. A room 5m long and 4m wide = 20 m². For irregular rooms, divide into rectangles and add the areas. For a room in feet: 15ft × 12ft = 180 sq ft. Convert to m²: divide by 10.764 (180 sq ft ≈ 16.7 m²).

How do I calculate the area of a circle?

Area = π × r² where r is the radius (half the diameter). A circle with diameter 6m has radius 3m: Area = 3.14159 × 3² = 28.27 m². For a circular table with 120cm diameter: radius = 0.6m, Area = 3.14159 × 0.36 = 1.13 m².

How do I calculate the area of a triangle?

Area = ½ × base × height. The height must be perpendicular to the base. For a triangle with base 8m and height 5m: Area = 0.5 × 8 × 5 = 20 m². For right triangles, the two legs are base and height.

How do I calculate square footage of a floor?

Measure length and width in feet and multiply. For an L-shaped room, divide into two rectangles, measure each, and add. For a 12ft × 15ft room = 180 sq ft. To convert to m²: multiply by 0.0929 (180 sq ft ≈ 16.7 m²).