Degrees to Radians Converter

Convert degrees (°) to radians instantly and accurately

Common Angle Conversions

About Degrees to Radians Conversion

Converting from degrees to radians is essential in many mathematical and scientific calculations. Degrees are commonly used in everyday contexts, while radians are the standard unit in calculus, physics, and engineering.

Conversion Formula

To convert from degrees to radians, multiply the angle value by π/180. The formula is:

radians = degrees × (π/180)

Common Degrees to Radians Conversions

Degrees to Radians Conversion Table

Degrees (°)Radians (rad)
30°π/6 ≈ 0.5236 rad
45°π/4 ≈ 0.7854 rad
60°π/3 ≈ 1.0472 rad
90°π/2 ≈ 1.5708 rad
120°2π/3 ≈ 2.0944 rad
180°π ≈ 3.1416 rad
270°3π/2 ≈ 4.7124 rad
360°2π ≈ 6.2832 rad

Practical Examples

Here are some practical examples of degrees to radians conversions:

  • In trigonometry, sin(30°) = sin(π/6) = 0.5, where 30° is converted to π/6 radians for the calculation.
  • When calculating the arc length of a circle, the formula s = r × θ requires the angle θ to be in radians. For example, a 90° arc on a circle with radius 5 units has length s = 5 × (90 × π/180) = 5 × (π/2) = 7.85 units.
  • In physics, angular velocity is often measured in radians per second. A rotation of 360° per second is equivalent to 2π radians per second.

Why Use Radians?

Radians are the natural unit for measuring angles in mathematics and physics for several reasons:

  • The derivatives and integrals of trigonometric functions take their simplest form when angles are measured in radians.
  • The small-angle approximation (sin θ ≈ θ for small angles) is only valid when θ is measured in radians.
  • In a circle, the radian measure of an angle is equal to the ratio of the arc length to the radius, making it a natural geometric measure.