Degrees to Radians
Since 180° is π radians, multiply degrees by π/180. The second figure is the multiple of π, so you can match π/2 or 2π at a glance.
Your numbers
Radians
3.141593rad
Result
1
Formula
Radians = Angle (°) × π ÷ 180
Trig functions in nearly every programming language take radians — passing degrees silently gives wrong answers.
What to enter
| Input | Default | Accepted range |
|---|---|---|
| Angle (°) (°)An angle in degrees; a full turn is 360°. | 180 | -3,600 ~ 3,600 |
Step by step
Quick reference table
Results when only Angle (°) (°) changes and everything else stays put.
| Angle (°) (°) | Radians (rad) | Result |
|---|---|---|
| 90 | 1.570796 | 0.5 |
| 135 | 2.356194 | 0.75 |
| 180 | 3.141593 | 1 |
| 270 | 4.712389 | 1.5 |
| 360 | 6.283185 | 2 |
What each result means
| Result | At default values |
|---|---|
| Radians (rad)An angle in radians; a full turn is 2π. | 3.141593 |
| ResultWhat the formula gives back — the answer this page is for. | 1 |
Common mistakes
Trig functions in nearly every programming language take radians — passing degrees silently gives wrong answers.
Glossary
- Angle (°)
- An angle in degrees; a full turn is 360°.
- Radians
- An angle in radians; a full turn is 2π.
- Result
- What the formula gives back — the answer this page is for.
Frequently asked questions
Q. How is Degrees to Radians calculated?
Radians = Angle (°) × π ÷ 180 — Since 180° is π radians, multiply degrees by π/180. The second figure is the multiple of π, so you can match π/2 or 2π at a glance.
Q. Can you walk through an example?
With Angle (°) 180°, the answer is Radians 3.141593rad.
Q. What do I need to enter?
Enter Angle (°). The result recalculates as you type, and an empty box counts as zero.
Q. How much does the answer move if I change a number?
Changing only Angle (°) (°) moves the answer to Angle (°) (°) 90 → Radians (rad) 1.570796 and Angle (°) (°) 360 → Radians (rad) 6.283185. The table below lays out five steps.
Q. How are the numbers rounded?
Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.
Q. Anything to watch out for?
Trig functions in nearly every programming language take radians — passing degrees silently gives wrong answers.
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