Circle Sector Calculator
Calculate circle sector area, arc length, and related values from a radius and central angle in degrees or radians.
Formulas:
Area = 1/2 × r² × θ (radians)
Arc length = r × θ (radians)
Result will appear here.
| Metric | Value |
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Privacy: calculations run locally in your browser. No inputs are stored or transmitted.
How it works
A sector is the slice of a circle bounded by two radii and the connecting arc.
- Sector area: 1/2 × r² × θ (radians)
- Arc length: r × θ (radians)
- Full circle area: πr²
- Circumference: 2πr
Examples
- r = 5, θ = 60° → sector area and arc length
- r = 10, θ = π/2 rad → quarter-circle sector
- r = 3, θ = 180° → semicircle sector
FAQ
- What does this circle sector calculator compute?
It computes sector area, arc length, full-circle area, and circumference from a radius and a central angle.
- Can I enter the angle in degrees or radians?
Yes. The calculator supports both degrees and radians.
- What is the formula for sector area?
In radians, sector area = 1/2 × r² × θ. In degrees, sector area = (θ / 360) × πr².
- What is the formula for arc length?
In radians, arc length = r × θ. In degrees, arc length = (θ / 360) × 2πr.
- Are calculations stored?
No. Everything runs locally in your browser.