Sector Area Calculator
Area of a pie slice of a circle.
Enter your values
Enter the radius you are working with.
Enter the central angle in degrees.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Sector area
- 52.3599
- Arc length
- 10.472
- Segment area
- 9.0586
- Chord length
- 10
- Share of full circle
- 16.67%
Quick answer
A sector's area is half the radius squared times the angle in radians.
A = ½r²θ
At a glance
| What it does | Area of a pie slice of a circle. |
|---|---|
| Category | Math |
| Inputs needed | Radius, Central angle |
| Main output | Sector area |
| Formula | A = ½r²θ |
| Cost | Free — no sign-up, no download |
How to use the Sector Area Calculator
- 1Enter the circle radius.
- 2Enter the sector's central angle in degrees.
- 3Read sector and segment areas.
Inputs explained
- Radius
- Enter the radius you are working with.
- Central angle(degrees)
- Enter the central angle in degrees.
Worked example
Using the values the calculator loads with:
Inputs
- Radius10
- Central angle60 degrees
Results
- Sector area52.3599
- Arc length10.472
- Segment area9.0586
- Chord length10
- Share of full circle16.67%
Frequently asked questions
What is a segment?
The region between a chord and the arc — the sector minus the triangle.
How do I get the angle from the arc?
Divide arc length by radius for radians.
What do I need to enter into the Sector Area Calculator?
Just 2 values: radius, central angle. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Sector Area Calculator work out the answer?
A sector's area is half the radius squared times the angle in radians. It applies the formula A = ½r²θ and shows the working so you can check each step by hand.
Is the Sector Area Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.