Area Calculator

Calculate area of rectangles, circles, triangles, and more

About Area Calculator

An area calculator finds the two-dimensional space enclosed by a shape — rectangles, circles, triangles, and more — using the formula specific to that shape. It's used in construction, landscaping, real estate, and any project where you need to know how much surface a shape covers.

Formula

Rectangle: Area = Length × Width | Circle: Area = π × r² | Triangle: Area = ½ × Base × Height

How It Works

Select the shape you want to calculate the area for
Enter the required dimensions for that shape (e.g., length and width for a rectangle, radius for a circle)
The calculator applies the correct formula for that shape
Result is shown in your chosen unit, squared (e.g., square feet, square meters)

Tips

Always keep units consistent — mixing feet and inches without converting will give an incorrect area
For irregular shapes, break them into rectangles and triangles, calculate each separately, and add the results
Circle area uses the radius (distance from center to edge), not the diameter — divide diameter by 2 first if that's what you have

Frequently Asked Questions

How do I calculate the area of a circle?

Area = π × radius². For example, a circle with radius 5 has an area of π × 25 ≈ 78.54 square units.

How do I calculate the area of a triangle?

Area = ½ × base × height. For a triangle with a base of 10 and height of 6: ½ × 10 × 6 = 30 square units.

What's the difference between area and perimeter?

Area measures the space enclosed within a shape (in square units); perimeter measures the total distance around its edges (in linear units) — they answer different questions and aren't interchangeable.

How do I calculate area for an irregular shape?

Divide the shape into simpler shapes (rectangles, triangles) you can calculate individually, then add all the areas together for the total.

How do I convert square feet to square meters?

Multiply square feet by 0.092903 to get square meters. For example, 500 sq ft × 0.092903 ≈ 46.45 sq m.