Square Footage of a Circle Calculator

Enter the radius or diameter with unit selection to calculate the square footage of a circular area.

Enter Dimensions

Result

Square Footage
78.539816
sq ft
Radius (in feet)5
Diameter (in feet)10
Circumference (ft)31.415927
Square Yards8.726646
Square Meters7.296055

Step-by-Step Solution

How to Calculate the Square Footage of a Circle

The area of a circle is calculated using the formula A = pi x r². To find the square footage, convert the radius (or half the diameter) to feet, then apply the formula.

Circle Area Formulas

From Radius

The most common formula using the radius.

A = pi x r²

From Diameter

Using diameter instead of radius.

A = pi x (d/2)²

Circumference

The distance around the circle.

C = 2 x pi x r

Common Uses

  • Calculating patio or deck area for circular designs.
  • Estimating material for circular garden beds or planters.
  • Determining coverage for round pools, fountains, or fire pits.
  • Planning paint or flooring for circular rooms or areas.
  • Calculating the area of circular driveways or turnarounds.

Conversion Reference

1 foot = 12 inches, 1 yard = 3 feet, 1 meter = 3.28084 feet. Always ensure your radius or diameter is converted to feet before calculating for square footage results.