Area calculator

Pick a shape and enter its measurements in any one unit. The area comes out in that unit squared.

Questions people ask

How do I find the area of a room in square feet or metres?

Measure the length and width in the same unit and multiply. A 12 ft × 15 ft room is 180 sq ft; a 4 m × 5 m room is 20 m². Split L-shaped rooms into rectangles and add them.

Why is the ellipse perimeter approximate?

There is no exact simple formula. This uses Ramanujan’s second approximation, which is accurate to a tiny fraction of a percent for any ellipse.