Convert Angle from radians to degrees (rad to deg)

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Single conversion

radian to degree Conversion Formula

Understanding the Conversion

To convert a specific radian measure into degrees, it helps to understand the relationship between these two units. A complete revolution of a circle is 2π radians, which is equivalent to 360 degrees. Simplifying this relationship, π radians is exactly equal to 180 degrees.

Because the radian is a derived unit in the International System of Units (SI), converting it to the more familiar unit of angular measure, the degree, requires a simple calculation.

The Formula

To calculate the value in degrees π is included in the conversion ratio. The formula is:

  • Degrees = Radians × 180π

Conversion Example

Let's say you want to convert an angle of π/6 radians.

  1. Multiply the radian value by 180/π.
  2. Calculation: (π/6) × (180/π) = 180 / 6.
  3. The result is 30 degrees.

You can perform this calculation manually for any angle, or simply use our radians to degrees calculator at the top of this page for instant, precise results.

How many radians are in one degree? One degree (deg) contains 0.017453292519943294444 radians (rad) — the inverse of the factor above. Multiplying by 57.295779513082325226 takes you from radians to degrees; multiplying by 0.017453292519943294444 brings you back.

Put in words: one radian equals 57.295779513082325226 degrees, so the radian is the larger unit of this pair. Converting between them never changes the amount of angle being measured — only the size of the unit you count it in.

What is a radian (rad)?

A radian (rad) is the standard unit used to measure angles, and it's part of the International System of Units (SI).

One radian is equal to roughly 57.3 degrees (deg), or more precisely, 180/π degrees.


Why Do We Use Radians?

The radian is the official SI unit for angles, making it the preferred choice in science and engineering.

It is especially common in fields like physics, calculus, and computer graphics. The main advantages of using radians are:

  • They simplify many essential mathematical and scientific formulas.
  • They create a direct link between a circle's angle and its arc length and radius.
  • They are the standard for higher-level mathematics, ensuring consistency in calculations.

How to Convert Radians to Degrees

A full circle has 360 degrees (360°), which is equal to 2π radians.

This key relationship gives us the precise formulas for converting between radians and degrees:

  • To convert radians to degrees: Degrees = Radians × (180/π)
  • To convert degrees to radians: Radians = Degrees × (π/180)

Here are some common angle conversions:

DegreesRadians (exact)Radians (approx.)
30°π/6 rad0.524 rad
45°π/4 rad0.785 rad
60°π/3 rad1.047 rad
90°π/2 rad1.571 rad
180°π rad3.142 rad
360°2π rad6.283 rad

What is the Definition of a Radian?

Geometrically, the definition of a radian is based on a circle's own properties.

Imagine an arc along the edge of a circle that has the same length as the circle's radius. The angle created at the center of the circle by this specific arc is exactly one radian.

Because a radian is a ratio of two lengths (arc length divided by radius), it is technically a dimensionless unit. This unique property is why it integrates so smoothly into advanced math and physics formulas.

What is a Degree (deg or °)?

In geometry and everyday life, we measure angles using degrees.

A degree (represented by the universal symbol °) is the basic unit for measuring rotation. It helps us describe the amount of turn between two lines that meet at a point.

For instance, a perfect corner, like the edge of a book, is a 90° right angle, and one complete, full-circle rotation measures 360°.


Why Are There 360 Degrees in a Circle?

The standard of a circle containing 360 degrees (360°) originated with the ancient Babylonians.

They used a base-60 (sexagesimal) number system, and 360 was a perfect number for them because it is highly divisible. Its large number of factors made it incredibly easy to perform fractional calculations in fields like astronomy and geometry.


How to Measure Angles Smaller Than a Degree

For fields that require extreme precision, like astronomy, cartography (map-making), and GPS navigation, a single degree is broken down into even smaller units:

  • One degree is subdivided into 60 arcminutes (symbolized as ').
  • Each arcminute is further divided into 60 arcseconds (symbolized as ").

This system ensures that even the tiniest angles can be measured with high accuracy.


Why a Circle Has 360 Degrees

There is no physical reason a full turn must be 360 of anything. The number is an inheritance from Babylonian astronomy, and it survived for two reasons that still matter.

The first is the calendar. Babylonian astronomers worked with a year of roughly 360 days, so the Sun appeared to advance about one degree along the ecliptic each day — a convenient bookkeeping unit for tracking the sky.

The second is arithmetic, and it is the reason the convention outlived the astronomy. 360 has 24 divisors. It splits evenly into halves, thirds, quarters, fifths, sixths, eighths, ninths, tenths, twelfths, fifteenths, eighteenths, twentieths, twenty-fourths and more. Every common fraction of a turn lands on a whole number of degrees: a right angle is 90°, a third of a turn is 120°, an eighth is 45°. A base-10 alternative such as the gradian, with 400 to a circle, is better for decimal arithmetic but produces fractions for thirds and sixths — which is roughly why it never displaced the degree outside surveying.


Degrees and Radians in Practice

Degrees are for people; radians are for mathematics and for machines.

The distinction is not stylistic. In calculus the derivative of sin(x) is cos(x) only when x is in radians; in degrees an awkward factor of π/180 appears and never leaves. Because of this, essentially every programming language's trigonometric library — JavaScript, Python, C, Java — takes radians, not degrees.

That mismatch is a reliable source of bugs. A value that looks plausible but is wrong by a factor of about 57.3 usually means degrees were passed where radians were expected. The conversions worth memorising are:

  • radians = degrees × π / 180
  • degrees = radians × 180 / π
  • One radian is about 57.2958°; one degree is about 0.0174533 radians.

Scientific calculators expose the same trap through their DEG / RAD / GRAD mode switch, where an unnoticed mode is the classic cause of an answer that is confidently and completely wrong.

radian to degree Conversion Table

Here are some quick reference conversions from radian (rad) to degree (deg):

radiansdegrees
0.000001 rad0.000057295779513082325226 deg
0.001 rad0.057295779513082325226 deg
0.1 rad5.7295779513082325226 deg
1 rad57.295779513082325226 deg
2 rad114.59155902616465045 deg
3 rad171.88733853924697568 deg
4 rad229.1831180523293009 deg
5 rad286.47889756541162613 deg
6 rad343.77467707849395136 deg
7 rad401.07045659157627658 deg
8 rad458.36623610465860181 deg
9 rad515.66201561774092703 deg
10 rad572.95779513082325226 deg
20 rad1145.9155902616465045 deg
30 rad1718.8733853924697568 deg
40 rad2291.831180523293009 deg
50 rad2864.7889756541162613 deg
100 rad5729.5779513082325226 deg
1000 rad57295.779513082325226 deg
10000 rad572957.79513082325226 deg

This conversion in other languages

Engineering datasheets across Europe write radian to degree several different ways. The calculation is the same in every one of them.

LanguageWritten asUnit names
Frenchrad en degradiandegré
Spanishrad a degradiángrado
Dutchrad naar degradiaalgraad
Germanrad in degRadiantGrad
Polishrad na degradianstopień