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  5. Angle Converter
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  7. Convert degree to radians

Convert degree to radians

Convert Degree (°) to Radian (rad) instantly.

Calculation

value × 0.0174532925199

Quick ConversionConverted
1 °0.017453 rad
5 °0.087266 rad
10 °0.174533 rad
100 °1.745329 rad
1,000 °17.453293 rad

Degree

A degree is an angle unit equal to one three-hundred-sixtieth of a full circle.

Degrees have ancient roots in astronomy and geometry and remain the most familiar everyday angle unit.

Degrees are used in geometry, navigation, surveying, mapping, drafting, weather direction, and user-facing angle measurements.

Radian

A radian is an angle unit where the arc length equals the radius of the circle.

Radians became central in mathematics because they simplify relationships between angles, arcs, and trigonometric functions.

Radians are used in trigonometry, calculus, physics, engineering, robotics, programming, and signal analysis.

How to Convert Degree to Radian

Mathematically, radian (rad) = degree (°) converted with the formula below.

1 ° = 0.017453 rad

1 rad = 57.29578 °

Formula: value × 0.0174532925199

Example: 15 ° = 0.261799 rad

  1. Start with the angle value in degrees.
  2. Use the relationship that 180 degrees equals pi radians.
  3. Multiply the degree value by pi.
  4. Divide by 180 to get radians.

Precision note: Use radians = degrees x pi / 180. Keep pi precision appropriate for the calculation rather than rounding the conversion too early.

How many ° in rad and rad in °

1 ° = 0.017453 rad

1 rad = 57.29578 °

Degree [°]Radian [rad]
0.01 °0.000175 rad
0.1 °0.001745 rad
1 °0.017453 rad
2 °0.034907 rad
5 °0.087266 rad
10 °0.174533 rad
20 °0.349066 rad
50 °0.872665 rad
100 °1.745329 rad

Common Use Cases for ° to rad

  • Preparing degree values for trigonometric functions in code or calculators.
  • Converting geometry or navigation angles into radians for math formulas.
  • Checking engineering, physics, or robotics calculations that expect radians.
  • Translating drafting or survey angles into the unit used by analytical equations.

FAQ

How many radians are in one degree?

One degree equals pi divided by 180 radians, or about 0.01745329252 rad.

What is 90 degrees in radians?

90 degrees equals pi divided by 2 radians, or about 1.570796327 rad.

Why do many formulas use radians?

Radians connect angle directly to arc length and make trigonometric and calculus formulas simpler.

More Degree conversions

  • degree to gradian
  • degree to arcminute
  • degree to arcsecond