Radian Converter
Convert an angle from degrees to radians with exact fractional-pi form when possible.
Inputs
Radians
3.1415926536
Exact form
1π
Step by step
Multiply by π/180
180° × π/180
= 3.1415926536 rad
Exact form
= 1π
How it works
To convert degrees to radians, multiply by π/180. Common angles have exact fractional-pi forms: 90° = π/2, 60° = π/3, 45° = π/4, 30° = π/6.
Formula
Degree to Radian
radians = degrees × π / 180
- deg
- Angle in degrees
- rad
- Angle in radians
Frequently Asked Questions
Why use radians instead of degrees?
Radians are the natural unit in calculus and physics. The derivative of sin(x) is cos(x) only when x is in radians. One radian is the angle subtended by an arc equal in length to the radius.
How many radians in a full circle?
2π radians = 360°. So π radians = 180°, and 1 radian ≈ 57.2958°.