Circle calculator

Enter any one measurement — diameter, radius, circumference, or area — and we'll solve for the rest. Handy as a pool circumference calculator for coping and cove.

I know the

Value

Result

Circumference75.40ft

Radius12.00 ft

Area452.39 sq ft

Estimate only — uses π ≈ 3.14159.

Circle formulas

Circumference = π × diameter. Area = π × radius². Radius is always half the diameter. Enter any one value and this circle calculator solves the rest using those three formulas.

Frequently asked questions

Select "Diameter" above, enter the distance straight across your pool, and the circumference (useful for ordering pool coping or cove) appears as the primary result.

Select "Circumference" above and enter the measured distance around the circle — diameter, radius, and area are calculated automatically.