Circle Calculator — Area, Circumference, Arc & Sector

Free circle calculator for area, circumference, diameter, arc length, and sector area — 100% client-side. 100% serverless.

🔒 100% Private

⚡ Completely Free

🌐 Runs in Browser

📦 Export Ready

⚡

Circle Calculator — Area, Circumference, Arc & Sector

Tool Workspace

Ready

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Enter Radius — The circle's radius.
Set Arc Angle — Optional angle for arc/sector calculations.
Calculate — See area, circumference, arc length, and sector area.

Circle Calculator

Calculate area, circumference, diameter, arc length, and sector area from a radius value.

Features

Area and circumference
Arc length and sector area
Customizable arc angle

Privacy

All calculations run in your browser.

Frequently Asked Questions

What formulas are used?

Area = πr², Circumference = 2πr, Arc = (θ/360)×2πr, Sector = (θ/360)×πr².

Can I calculate for a specific arc?

Yes. Enter an arc angle (0-360°) to get arc length and sector area.

Is my data safe?

Yes. 100% in your browser.

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