Arc Length Calculator
Compute the arc length of a circle given its radius and central angle in degrees.
About Arc Length Calculator
Arc length is the distance along the curved part of a circle. It equals the radius times the central angle in radians.
Formula
Arc Length
L = r × θ (θ in radians)
- r
- Radius
- θ
- Central angle in radians
Worked example
With the default values below, Arc Length Calculator returns Arc Length of 15.7080. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Radiusminimum 0 units
- 10 units
- Central Angleaccepts 0–360 °
- 90 °
Results
- Arc Length
- 15.7080 units
Step by step
- 1Convert angle to radians
- 2Arc length= 15.7080
Assumptions and limits
- The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How do I convert degrees to radians?
Multiply degrees by π/180. For example, 90° = π/2 radians.
What is the arc length for a full circle?
It equals the circumference: 2πr (360° gives θ = 2π).