How do I convert degrees to radians?

Multiply degrees by π and divide by 180. So 180 degrees is exactly π radians, and 90 degrees is π/2. Most programming languages and scientific calculators expect angles in radians, which is the most common reason people need this conversion.

A gradian, also called a gon, divides a right angle into 100 parts, so a full circle is 400 gradians rather than 360 degrees. It is used in some surveying and engineering contexts because it fits the decimal system neatly.

How accurate are the conversions?

Each conversion uses the exact, internationally defined factor for the unit, not a rounded approximation, so the maths is precise. The result is shown to several significant figures and rounded only for display. For everyday and most professional use, the figures are exact to well beyond the precision you need.

Does this work offline and is anything sent to a server?

The conversion runs entirely in your browser, so nothing you type is sent anywhere, and once the page has loaded it keeps working with no connection. There is no sign-up and no limit on how many conversions you make.

Angle Converter

Convert angles between degrees, radians, gradians, turns, arcminutes and arcseconds. Type a value and see it in every unit at once, exactly. A free angle converter for maths, engineering and programming, in your browser.

Exact, standard factors
100% free
No sign-up, no app
Instant as you type
Works offline after first load

Convert

From

0.01745329rad

1 ° = 0.01745329 rad

1 ° in every unit

Degree1 °

Radian0.01745329 rad

Gradian1.1111111 grad

Turn0.00277778 turn

Arcminute60 ′

Arcsecond3,600 ″

How to use it

1
Enter a value

Type the number you want to convert. The result updates as you type, with no button to press.
2
Pick the units

Choose what you are converting from and to. Swap them with one click if you need the reverse.
3
Read or copy

See the exact result, plus a table of your value in every unit. Copy any line you need.

When it comes in handy

Maths and trigonometry

Convert degrees to radians for trig functions, which most calculators and code expect in radians.

Programming

Switch between degrees and radians when a graphics or game library uses one and your data uses the other.

Surveying and astronomy

Work with arcminutes and arcseconds for fine angular measurements.

Instant, exact & 100% in your browser

The conversion runs right here in your browser using exact, standard factors. Nothing you type is sent to a server, there is no sign-up and no limit, and once the page has loaded it keeps working even with no connection.

Frequently asked questions

How do I convert degrees to radians?: Multiply degrees by π and divide by 180. So 180 degrees is exactly π radians, and 90 degrees is π/2. Most programming languages and scientific calculators expect angles in radians, which is the most common reason people need this conversion.
What is a gradian?: A gradian, also called a gon, divides a right angle into 100 parts, so a full circle is 400 gradians rather than 360 degrees. It is used in some surveying and engineering contexts because it fits the decimal system neatly.
How accurate are the conversions?: Each conversion uses the exact, internationally defined factor for the unit, not a rounded approximation, so the maths is precise. The result is shown to several significant figures and rounded only for display. For everyday and most professional use, the figures are exact to well beyond the precision you need.
Does this work offline and is anything sent to a server?: The conversion runs entirely in your browser, so nothing you type is sent anywhere, and once the page has loaded it keeps working with no connection. There is no sign-up and no limit on how many conversions you make.