Angle Converter

Degrees are the everyday angle unit, radians are what maths and programming functions expect, gradians appear in surveying, arcminutes and arcseconds in astronomy and map coordinates, and mils in military and shooting optics. A full turn is 360°, 2π radians, 400 gradians or 6,400 NATO mils.

How to use Angle Converter

1. Type the value you want to convert.
2. Choose the unit you have in From and the unit you want in To. The swap button turns the conversion round.
3. Read the answer, with the formula underneath. For example, 180° = π rad ≈ 3.14159 rad.
4. Open All units to see the value in every unit at once, and copy the one you need.

When it comes in handy

• Converting degrees to radians for code (Math.sin expects radians).
• Surveying and engineering drawings in gradians.
• Astronomy and scope adjustments in arcminutes and mils.

Frequently asked questions

How do I convert degrees to radians?

Multiply by π and divide by 180. 90° × π ÷ 180 = π/2 ≈ 1.5708 rad.

Why do calculators give odd answers for sin(90)?

They are probably in radians mode. sin(90 radians) ≈ 0.894, while sin(90°) = 1.