EVERYDAY CLARITY
Arc Length Calculator
How long is an arc with this radius and central angle? Enter the values below to calculate the result.
Your result
result
length
Result for the values shown.
Calculations run in your browser.
What to enter
| Input | Meaning and units |
|---|---|
| Radius (length) | Enter the radius, which is half the diameter. |
| Central angle (degree) | Enter central angle in degree; use the same basis as the other measurements. |
Understanding your result
Read result (length) in the units and model stated on this page. The formula result=r*theta*pi/180 defines the relationship; measurement accuracy and model applicability are separate from numerical precision.
Common mistakes
- Entering the diameter where the radius is requested.
Check your calculation
- Use the worked example as a known reference case, then change one input at a time and check the direction and units of the response.
Calculation checks, sources and review limits
How long is an arc with this radius and central angle?
How long is an arc with this radius and central angle? Enter the values below to calculate the result.
Common uses
- How long is an arc with this radius and central angle
How it works
result=r*theta*pi/180
Worked example
Enter Radius: 2 length; Central angle: 90 degree. Results: result: 3.141592653589793 length.