Circle Calculator
Calculate the area, diameter or circumference of a circle from any one of those values.
Circle formulas
d = 2r, C = 2ฯr, A = ฯrยฒ. Enter any one to compute the others.
Frequently Asked Questions
Is the Circle Calculator free to use?
Yes, the Circle Calculator is 100% free to use. There are no subscriptions, no sign-ups, and no hidden fees.
Is my data safe when using the Circle Calculator?
Absolutely. All calculations performed by the Circle Calculator happen locally in your web browser. We do not store, track, or transmit your inputs or results to any server.
How accurate is the Circle Calculator?
Our Circle Calculator uses industry-standard formulas and methodology. You can view the exact formula and calculation logic used in the methodology section above to verify the math yourself.
Can I use the Circle Calculator on my mobile phone?
Yes! The Circle Calculator is fully responsive and works seamlessly on all devices including smartphones, tablets, and desktop computers.