Degrees to Radians Converter

1 degree (°) equals 0.01745329252 radians (rad).

Quick answer

To convert degrees to radians, multiply by π/180 (about 0.017453): 90° = π/2 ≈ 1.5708 rad.

  • 1 degree = 0.01745329252 radians
  • 1 radian = 57.29577951 degrees
  • Formula: rad = ° × 0.01745329252
  • Quick estimate: multiply by 0.01745, or divide by 57.3.

1 degree = 0.01745329252 radians

How to convert degrees to radians

rad = ° × 0.01745329252

To convert degrees to radians, multiply the number of degrees by 0.01745329252.

Example: 42 ° to rad

  1. Start with the value in degrees: 42 °.
  2. Multiply by 0.01745329252: 42 × 0.01745329252 = 0.7330382858.
  3. Result: 42 degrees = 0.7330382858 radians.

Going the other way, 1 radian = 57.2957795131 degrees, so to convert radians back to degrees you divide by the same number. See radians to degrees.

Where the conversion factor comes from

A full circle is 360 degrees or 2π radians, so π rad = 180°, 1 rad = 180/π ≈ 57.2958° and 1° = π/180 ≈ 0.0174533 rad. A radian is the angle whose arc length equals the radius, which is why calculus and physics formulas use radians.

Mental math: ° to rad in your head

Divide by 57.3. Common angles: 30° = π/6, 45° = π/4, 60° = π/3, 90° = π/2, 180° = π, 360° = 2π.

When you need to convert degrees to radians

  • Programming (sin, cos and tan functions use radians).
  • Physics, calculus and engineering.

Common mistakes

  • Passing degrees to Math.sin() or sin() in code, which expect radians.
  • Leaving a calculator in the wrong angle mode.

Everyday degrees in radians

ExampleDegreesRadians
30°30 °0.5236 rad
45°45 °0.7854 rad
60°60 °1.0472 rad
90°90 °1.5708 rad
180°180 °3.1416 rad
360°360 °6.2832 rad

Degrees to radians conversion table

Degrees (°)Radians (rad)
0.1 ° 0.001745329252 rad
0.2 ° 0.003490658504 rad
0.3 ° 0.005235987756 rad
0.4 ° 0.006981317008 rad
0.5 ° 0.00872664626 rad
0.6 ° 0.01047197551 rad
0.7 ° 0.01221730476 rad
0.8 ° 0.01396263402 rad
0.9 ° 0.01570796327 rad
1 ° 0.01745329252 rad
1.5 ° 0.02617993878 rad
2 ° 0.03490658504 rad
2.5 ° 0.0436332313 rad
3 ° 0.05235987756 rad
3.5 ° 0.06108652382 rad
4 ° 0.06981317008 rad
4.5 ° 0.07853981634 rad
5 ° 0.0872664626 rad
6 ° 0.1047197551 rad
7 ° 0.1221730476 rad
7.5 ° 0.1308996939 rad
8 ° 0.1396263402 rad
9 ° 0.1570796327 rad
10 ° 0.1745329252 rad
11 ° 0.1919862177 rad
12 ° 0.2094395102 rad
13 ° 0.2268928028 rad
14 ° 0.2443460953 rad
15 ° 0.2617993878 rad
16 ° 0.2792526803 rad
17 ° 0.2967059728 rad
18 ° 0.3141592654 rad
19 ° 0.3316125579 rad
20 ° 0.3490658504 rad
21 ° 0.3665191429 rad
22 ° 0.3839724354 rad
23 ° 0.401425728 rad
24 ° 0.4188790205 rad
25 ° 0.436332313 rad
26 ° 0.4537856055 rad

More ° to rad values

What is a degree?

The degree is the most common unit of angle: a full rotation is 360 degrees and a right angle 90.

More about degrees →

What is a radian?

The radian is the SI unit of angle: the angle at the center of a circle where the arc length equals the radius.

More about radians →

Frequently asked questions

How many radians are in a degree?

One degree is 0.01745329252 radians.

How many degrees are in a radian?

One radian is 57.29577951 degrees.

What is the formula to convert degrees to radians?

rad = ° × 0.01745329252.

How many radians is 180 degrees?

π radians (3.14159).