Free Angle Converter Online

The Angle Converter is a free online tool that converts between degrees, radians, and gradians for mathematical and engineering calculations.

Yes, it is completely free with no registration required. All conversions happen client-side in your browser.

The Angle Converter supports degrees, radians, gradians (gons), turns, and arc minutes/seconds.

Absolutely. The Angle Converter processes everything client-side in your browser. No data is uploaded to or stored on any server. Your content remains private on your device at all times.

Yes, the Angle Converter is fully responsive and works on smartphones and tablets. You can use it on any device with a modern web browser -- no app download required.

No account or registration is needed. Simply open the Angle Converter in your browser and start using it immediately. There are no sign-up walls or usage restrictions.

Simply enter your input in the provided field, adjust any settings to your preference, and the tool will process it instantly. You can then copy the result to your clipboard or download it.

The Angle Converter works in all modern browsers including Chrome, Firefox, Safari, Edge, and Opera. For the best experience, use the latest version of your preferred browser.

To convert degrees to radians, multiply the degree value by pi divided by 180, because a full circle is 360 degrees and also 2 pi radians. So 180 degrees equals pi radians (about 3.14159), 90 degrees equals pi/2, and 45 degrees equals pi/4. To go the other way, multiply radians by 180/pi. This matters because nearly every programming language's sin, cos, and tan functions expect radians, not degrees, so feeding them raw degree values quietly produces wrong results. The relationship is exact arithmetic, but doing it by hand invites rounding mistakes. Enter your degree value in the Angle Converter, choose Radians as the target unit, and it returns the precise result to six decimal places, with a one-tap swap to reverse the direction whenever you need it.

Degrees and gradians both measure plane angles but divide the circle differently. A full circle is 360 degrees but 400 gradians (also called gons), which makes a right angle exactly 100 gradians instead of 90 degrees. The gradian was designed for that round number, so a quarter turn is 100 gradians, a half turn is 200, and a slope of 1 gradian is 1 percent grade. Gradians appear mainly in surveying, civil engineering, and some European calculators, while degrees dominate everyday geometry and navigation. To convert, multiply degrees by 10/9 to get gradians, or gradians by 9/10 to get degrees. The Angle Converter handles both directions instantly and also shows the exact unit-to-unit factor, so you can see that 1 degree equals roughly 1.111 gradians at a glance.

A NATO mil is an angular unit used by militaries for artillery and rangefinding, defined so that a full circle contains exactly 6400 mils. That makes one mil equal to 360/6400, or 0.05625 degrees, and a right angle 1600 mils. The appeal is practical: at long range one mil subtends roughly one meter per 1000 meters of distance, which simplifies aiming and ranging math in the field. Note that not all mils agree: Soviet doctrine splits the circle into 6000 mils and Swedish streck uses 6300, so the same word can mean slightly different angles. The Angle Converter includes NATO mils, Soviet mils, and Swedish streck side by side, letting you translate any of them to and from degrees or radians accurately rather than relying on a remembered approximation.

Arcminutes and arcseconds subdivide a single degree using the same sexagesimal system as clocks. One degree contains 60 arcminutes (symbol prime), and one arcminute contains 60 arcseconds (symbol double prime), so a degree holds 3600 arcseconds. These fine units describe very small angles in astronomy, optics, and precision aiming, where a whole degree is far too coarse; the apparent size of a planet or the resolution of a telescope is often quoted in arcseconds. They also map directly onto latitude and longitude, where coordinates are written in degrees, minutes, and seconds. The Angle Converter not only translates between these units but also displays a degrees-minutes-seconds breakdown for any angle you enter, so you can read a decimal degree value as its exact DMS equivalent without separate calculation.

Most languages use radians because radians are the natural mathematical unit for angles, defined by the geometry of the circle itself rather than an arbitrary count. One radian is the angle where the arc length equals the radius, so arc length is simply radius times angle in radians with no conversion constant. This keeps calculus clean: the derivative of sine is cosine only when the input is in radians, and the series expansions used internally to compute trig functions assume radians. As a result, functions like Math.sin in JavaScript, Python, C, and Java all expect radian inputs, which is a frequent source of bugs when a value is actually in degrees. The Angle Converter makes the handoff easy, converting any degree value to radians at the precision you choose so you can paste a correct argument straight into your code.