Angle Converter — Degrees, Radians, Gradians & DMS
Convert between 13 angle units simultaneously — type in any field and all others update instantly. Includes DMS (degrees–minutes–seconds) compound input, a live unit circle visualiser, trig values, and common angles quick-fill. Free, no account.
Type any value — all 13 units + DMS update instantly
Enter an angle in any unit. The unit circle, trig values, and pi notation update live.
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How to convert angle units
The most complete free online angle converter
Angle Unit Conversion — Degrees, Radians, Gradians & DMS Complete Guide
Angles can be measured in many different units. Degrees are the most familiar — a full circle is 360°. Radians are the standard mathematical unit where a full circle equals 2π radians. Gradians (also called gon) divide a right angle into 100 parts, so a full circle is 400 grad. Each system has advantages depending on the application.
Conversion formulas
Standard angle reference table
| Degrees | Radians (exact) | Radians (decimal) | Gradians | sin | cos | tan |
|---|---|---|---|---|---|---|
| 0° | 0 | 0 | 0 | 0 | 1 | 0 |
| 30° | π/6 | 0.5236 | 33.33 | 0.5 | 0.8660 | 0.5774 |
| 45° | π/4 | 0.7854 | 50 | 0.7071 | 0.7071 | 1 |
| 60° | π/3 | 1.0472 | 66.67 | 0.8660 | 0.5 | 1.7321 |
| 90° | π/2 | 1.5708 | 100 | 1 | 0 | undef. |
| 120° | 2π/3 | 2.0944 | 133.33 | 0.8660 | -0.5 | -1.7321 |
| 180° | π | 3.14159 | 200 | 0 | -1 | 0 |
| 270° | 3π/2 | 4.7124 | 300 | -1 | 0 | undef. |
| 360° | 2π | 6.2832 | 400 | 0 | 1 | 0 |
Why radians are used in mathematics and programming
Radians are the natural unit for angles in mathematics. The radian is defined so that an arc of length r on a circle of radius r subtends an angle of 1 radian at the centre. This makes calculus formulas for trigonometric functions simpler: the derivative of sin(x) is cos(x) only when x is in radians. Programming languages and scientific calculators use radians by default for sin(), cos(), tan() functions. To use degrees with these functions, you must convert first: sin(degrees * PI / 180).
Gradians (gon) — the metric angle
Gradians (also called gon or grades) were introduced as part of the metric system to make angle arithmetic easier. The key advantage: a right angle is exactly 100 gradians, so right-angle multiples (slopes, compass bearings) are round numbers. Gradians are used in surveying (particularly in Continental Europe), land navigation, and some military applications. A full circle = 400 grad. Half circle = 200 grad. 1 gradian = 0.9 degrees = π/200 radians.
DMS — Degrees, Minutes, Seconds
DMS is the traditional format for geographic coordinates and astronomical measurements. Just as hours are divided into 60 minutes and 60 seconds, degrees are subdivided similarly. The Moon is 384,400 km away; its angular diameter is approximately 31’6” (31 arcminutes 6 arcseconds). GPS coordinates are often expressed as DMS: 51°30’26”N, 0°7’39”W (the Tower of London). Converting DMS to decimal degrees: DD = D + M/60 + S/3600.
Milliradians in military and firearms
The milliradian (mrad) is used for targeting and range estimation. At 1000 metres, 1 mrad subtends approximately 1 metre — this is the practical mil rule used in sniper and artillery applications. Rifle scopes calibrated in mrad allow precise elevation and windage adjustments. NATO uses a slightly different mil (1/6400 of a circle — not a true milliradian) while the Warsaw Pact used 1/6000. This converter uses the true mathematical milliradian (1/1000 of a radian).
Angle converter FAQ
Multiply by pi/180 (approximately 0.017453). Examples: 90 x pi/180 = pi/2 = 1.5708 rad. 180 degrees = pi rad. 360 degrees = 2*pi rad. Type degrees into the converter above and radians update instantly.
Multiply by 180/pi (approximately 57.2958). Examples: pi rad = 180 degrees. pi/2 rad = 90 degrees. 1 radian = 57.2958 degrees. 2*pi rad = 360 degrees.
A gradian divides a right angle into 100 parts. Full circle = 400 grad. To convert degrees to gradians, multiply by 10/9. To convert gradians to degrees, multiply by 9/10 (= 0.9). Used in surveying and Continental European land navigation.
1 degree = 60 arcminutes ('). 1 arcminute = 60 arcseconds ("). So 1 degree = 3600 arcseconds. Used in astronomy, GPS accuracy, and optics. The Moon's diameter is about 31 arcminutes. 1 arcsecond on Earth's surface is about 30 metres.
DMS = Degrees-Minutes-Seconds. Example: 47 degrees 26' 13" = 47 + 26/60 + 13/3600 = 47.4369 decimal degrees. Used for GPS coordinates, astronomy, and navigation. The DMS input above converts automatically when you change any field.
Exactly 2*pi radians (approximately 6.28318). Key values: quarter circle = pi/2 = 1.5708 rad = 90 degrees. Half circle = pi = 3.14159 rad = 180 degrees. Three-quarter = 3*pi/2 = 4.71239 rad = 270 degrees.
Binary degrees divide a full circle into 256 units (2^8). 256 binary degrees = 360 degrees. 128 = 180 degrees. 64 = 90 degrees. Used in game engines and embedded systems where integer arithmetic is preferred for angle storage.
The LazyTools Angle Converter is 100% free with no signup. Convert between 13 units and DMS simultaneously, see the live unit circle and trig values, load common angles. No account, no limits.