Degrees to Radians Converter

°
rad
Formula: radians = degrees × π / 180

Degrees to Radians Converter

Degrees and radians are two ways to measure angles. Radians are based on the radius of a circle — one radian is the angle where the arc length equals the radius.

Conversion Formula

radians = degrees × π / 180

Since a full circle is 360° = 2π radians, dividing both sides by 360 gives 1° = π/180 radians. Multiply any degree value by π/180 to convert.

Step-by-Step Examples

90° = 1.5707963268 rad

90° = π/2 radians, a quarter turn.

45° = 0.7853981634 rad

45° = π/4 radians, an eighth turn.

Frequently Asked Questions

How do you convert degrees to radians?

Multiply the degree value by π/180. For example, 90° × π/180 = π/2 ≈ 1.5708 radians.

Why do we use radians instead of degrees?

Radians simplify many mathematical formulas. In calculus, the derivative of sin(x) is cos(x) only when x is in radians.

What is π radians in degrees?

π radians equals exactly 180 degrees. This is the fundamental relationship between the two units.

How many radians is a full circle?

A full circle is 2π radians, which equals approximately 6.2832 radians.

What is 1 degree in radians?

1 degree equals π/180 ≈ 0.01745 radians.