Sector Calculator
Compute the area and arc length of a circular sector.
Amortization schedule
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Showing first 12 of months.
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Introduction
Sector Calculator — Compute the area and arc length of a circular sector. Enter Radius, Central angle (degrees) to get an instant, accurate result.
Formula
Sector area = πr² × (angle/360). Arc length = 2πr × (angle/360), where angle is the central angle in degrees.
Step-by-step
- Enter the Radius.
- Enter the Central angle (degrees).
- Click Calculate to see your result instantly.
Real-world example
Example: With Radius = 10, Central angle (degrees) = 90, the Sector Calculator gives Area: 78.5398, Arc Length: 15.708.
Frequently Asked Questions
What is a sector?
The pie-slice-shaped region of a circle bounded by two radii and the arc between them.
What if the angle is 90°?
The sector is a quarter of the full circle, so its area is a quarter of πr².
What inputs does the Sector Calculator need?
You'll need to provide: Radius, Central angle (degrees). All fields use sensible defaults, so you can see a working example immediately and then adjust the values to match your own numbers.
How accurate is the Sector Calculator?
The Sector Calculator applies the formula exactly as calculated — Sector area = πr² × (angle/360). Arc length = 2πr × (angle/360), where angle is the central angle in degrees. — so results are precise for the inputs you provide. Accuracy depends on entering correct, realistic input values.
Is the Sector Calculator free to use?
Yes, the Sector Calculator is completely free, requires no signup, and runs instantly in your browser.
About the Sector Calculator
The Sector Calculator uses a real, verifiable formula — Sector area = πr² × (angle/360). Arc length = 2πr × (angle/360), where angle is the central angle in degrees. — so results are accurate every time, not an approximation.