Free online angle converter
Angle measurement uses several unit systems. This converter handles all major angle units — degrees, radians, gradians, and more — with a full conversion table.
Saved to favorites
Your favorites live on the home page, under Your favorites. They're saved only on this device & browser — open the site on your phone or in another browser and you won't see them there. No account, no server.
How to use
- Enter a value.
- Select the unit you are converting from.
- Select the unit you want to convert to.
- The result and full conversion table appear instantly.
Supported units
| Unit | Symbol | Notes |
|---|---|---|
| Degrees | ° | Most common; 360° = full circle |
| Radians | rad | SI standard; 2π = full circle |
| Gradians | grad | 400 = full circle; used in surveying |
| Turns | — | 1 = full circle |
| Arcminutes | ′ | 1° = 60′ |
| Arcseconds | ″ | 1° = 3,600″ |
| NATO mils | mil | 6,400 = full circle |
Key conversions
| From | To | Factor |
|---|---|---|
| 1 degree | radians | π / 180 ≈ 0.017453 |
| 1 radian | degrees | 180 / π ≈ 57.2958 |
| 1 degree | gradians | 10/9 ≈ 1.1111 |
| 1 turn | degrees | 360 |
| 1 degree | arcminutes | 60 |
| 1 degree | arcseconds | 3,600 |
Worked example
180 degrees to radians:
180° × (π / 180) = π rad ≈ 3.14159 rad
This is the most common conversion — a half-circle (180°) equals exactly π radians.
Frequently asked
What is a radian?
A radian is the angle subtended when the arc length equals the radius. One full circle = 2π radians ≈ 6.2832 rad. Radians are the SI standard unit for angles in mathematics and physics.
What is the difference between degrees and gradians?
A full circle has 360 degrees or 400 gradians. Gradians (also called gon or grade) divide the right angle into 100 equal parts, making some surveying calculations simpler.
What is a turn?
One turn is a full rotation (360°). It simplifies cyclic calculations — 0.25 turn = 90°, 0.5 turn = 180°, etc. Also called revolution or cycle.
What are arcminutes and arcseconds?
One degree = 60 arcminutes (′). One arcminute = 60 arcseconds (″). These units are used in astronomy, GPS coordinates, and precise navigation.
What are NATO mils?
NATO mils divide a full circle into 6,400 units. One degree ≈ 17.78 mils. Mils are used in artillery and military targeting because small angular changes translate predictably to distance changes at range.
Embed this calculator
Add this free calculator to your own site. Copy the snippet — it works anywhere you can paste HTML, and stays in sync with this page.