Area Calculator
Calculate the area of rectangles, triangles, and circles.
How It Works
Rectangle: D1 × D2. Triangle: 0.5 × D1 × D2. Circle: π × Radius².
Example
A 10 ft × 12 ft rectangle is 120 sq ft; a circle with a 5 ft radius is about 78.5 sq ft.
Frequently Asked Questions
Which shape should I pick?
Rectangle for rooms and lots, triangle for gables and odd lots, circle for round patios or tanks.
What units does Dimension 1 use?
Feet — enter both dimensions in feet and the area comes out in square feet.
How do I handle irregular shapes?
Split them into rectangles and triangles and add the areas together.