Circle and Arc Calculator

• Free online circle & arc calculator
• In Circle mode, enter any one known value (radius, diameter, circumference, or area) and the tool computes all the others
• In Arc mode, enter combinations such as radius + central angle, radius + arc length, or chord + central angle to get arc length, chord length, sector area, and segment area

1. Open the tool page — no download or installation needed
2. Pick a mode (Circle or Arc), select what you know (e.g. radius, diameter, circumference, or area), then enter its value
3. Click "Calculate" and review the full results below — every value can be copied with one click

• This tool is completely free and requires no sign-up
• All calculations run locally in your browser — your data never leaves your device

Free online circle and arc calculator. Calculate circle parameters from radius, diameter, circumference, or area. Calculate arc length, chord length, sector area, and segment area from various combinations of known values.

Open the tool page — no download or installation needed Pick a mode (Circle or Arc), select what you know (e.g. radius, diameter, circumference, or area), then enter its value Click "Calculate" and review the full results below — every value can be copied with one click

This tool is completely free and requires no sign-up All calculations run locally in your browser — your data never leaves your device

Yes, Circle and Arc Calculator is completely free. No download or installation required — it runs right in your browser.