About this calculator
Enter an angle and choose the units.
How to use it
- Enter the value.
- Choose the unit it is in and the unit you want.
- Read the result, or see every unit in the table.
The formula
Radians = degrees × π ÷ 180
- 360°
- 2π radians = 400 gradians = 1 turn
- 1°
- 60 arcminutes = 3,600 arcseconds
Worked example
A right angle
- 90° = π ÷ 2 = 1.5708 rad.
- = 100 gradians.
- = 0.25 turn.
What the result means
The factors are exact international definitions, so results are as accurate as the digits shown.
Assumptions
- Plane angles.
Limitations
- None beyond rounding.
Frequently asked questions
How many radians in 180°?
π, about 3.1416.
How do I convert radians to degrees?
Multiply by 180 and divide by π.
What is a gradian?
1/400 of a turn, so a right angle is 100 gradians.
Last reviewed on 3 October 2026. Found a mistake? Tell us.