Gradians to radians
Type a value in gradians to see it in radians straight away, or type in the second box to convert back.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Type the value in the gradians box.
- Read the result in radians as you type, and pick the precision you need.
- Swap the direction to convert back, or copy the result.
How it is calculated
rad = gon × 0.01570796327
Multiply the value in gradians by 0.01570796327 to get radians.
Example
To convert 25 gon to radians: 25 × 0.01570796327 = 0.392699 rad.
Conversion table
| Gradians (gon) | Radians (rad) |
|---|---|
| 1 | 0.015708 |
| 2 | 0.0314159 |
| 3 | 0.0471239 |
| 5 | 0.0785398 |
| 10 | 0.15708 |
| 20 | 0.314159 |
| 25 | 0.392699 |
| 50 | 0.785398 |
| 100 | 1.5708 |
| 250 | 3.92699 |
| 500 | 7.85398 |
| 1,000 | 15.708 |
About the units
- Gradian
- The gradian (gon) is 1/400 of a full turn, exactly 0.9 degree, so a right angle is 100 gradians. It is used in European surveying.
- Radian
- The radian is the SI unit of angle: the angle subtended by an arc equal in length to the radius. It equals 180/π degrees, about 57.2958 degrees.
Limits and caveats
- Results are rounded for display and computed with the browser's floating point precision (about 15 significant digits).
- Both unit factors are exact by their official definitions.
Questions about this tool
How many radians are in one gradian?
1 gon = 0.015708 rad exactly.
How do I convert gradians to radians?
Use rad = gon × 0.01570796327. For example, 25 gon = 0.392699 rad.
How many gradians are in one radian?
1 rad = 63.662 gon.
Why does my calculator give a strange answer for sine?
It is probably set to radians (RAD) while you are entering degrees. The sine of 30 degrees is 0.5, but the sine of 30 radians is about -0.988, so switch to DEG first.
What is the difference between MOA and MIL on a rifle scope?
MOA is an arcminute, 1/60 of a degree, while a MIL is a milliradian, about 3.438 MOA. At 100 meters a 0.1 MIL click moves impact 1 cm, and 1 MOA moves it about 2.9 cm.