Angle Converter Free Online
Convert between angle units instantly. Supports degrees, radians, gradians, arcminutes, arcseconds, and full turns. Useful for math, geometry, trigonometry, surveying, astronomy, and CAD.
All Conversions
Pro — bulk batch conversion, API access, history & favorites
API access · Priority queue · Team workspace
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How It Works
Enter a Value
Type the number you want to convert into the From input. The conversion runs as you type — no Convert button needed. Decimals and very small or very large numbers are supported via scientific notation.
Pick Source & Target Units
Use the two dropdowns to choose source (From) and destination (To) units. The result updates automatically. Use the swap button to flip the conversion direction in one click.
See All Conversions
Below the main result, the All Conversions panel shows your input value converted into every supported unit at once — perfect for comparing metric vs imperial side by side.
Angle Converter Features
SI Radian
Radian is the SI angle unit. 1 full circle = 2π rad ≈ 6.283. Standard in physics, calculus, and programming (Math.sin, etc.).
Degrees
Degree (1/360 of a circle) is the everyday angle unit. Used in geometry, navigation, and CAD. 1 deg = π/180 rad.
Gradian
Gradian (1/400 of a circle) is used in some European surveying, where a right angle = 100 grad. Decimal subdivision makes it nice for slope calculation.
Arcmin & Arcsec
1 degree = 60 arcminutes = 3600 arcseconds. Standard for astronomy (star positions), GPS coordinates, and high-precision surveying.
Live Conversion
Result updates on every keystroke. Convert a calculator-friendly degree to a JS-friendly radian instantly.
100% Private
All math runs in your browser. Safe for any use case.
Free vs Pro
| Feature | Free | Pro |
|---|---|---|
| All 6 angle units | ||
| Live conversion | ||
| All-units result table | ||
| Bulk CSV / Excel conversion | — | |
| REST API access | — | |
| Custom precision settings | — |
Frequently Asked Questions
1 radian = 180/π ≈ 57.29578 degrees. 1 degree = π/180 ≈ 0.01745 rad. The radian is defined so that the arc length on a unit circle equals the angle in radians — that is why π appears.
1 turn = 1 full revolution = 360° = 2π rad ≈ 6.283 rad. Useful for physics (frequency in turns per second = Hz) and computer graphics.
1 gradian = 1/400 of a circle = 0.9°. So a right angle = 100 grad, a straight line = 200 grad. Used in some European surveying and old French math; almost extinct elsewhere.
None directly. 1 arcminute is an angle (1/60 deg). 1 minute of time is a duration (60 s). On the celestial sphere, 1 minute of time of right ascension corresponds to 15 arcminutes of arc (because Earth rotates 360° in 24 h).
Most likely degree/radian mode mismatch. JavaScript Math functions use radians; calculators default to degrees. sin(30°) = 0.5 but sin(30 rad) ≈ -0.988. Always check the mode.