Angle Converter

Convert between degrees, radians, gradians and turns.

What the Angle Converter does

A full circle is 360 degrees, 2π radians, 400 gradians or one turn. Radians are the natural unit for calculus and trigonometry because the arc length of a unit circle equals the angle itself.

Formula

  • Convert to degree, then divide by the target unit's factor
  • Result = Value × (from factor ÷ to factor)

Inputs explained

InputUnitRequiredNotes
ValuenumberYes
Fromone of 7 optionsYes
Toone of 7 optionsYes

How to use it

  1. Choose From and To.
  2. Enter Value.
  3. Select Calculate.

Worked example

Convert 90 degrees to radians.

Value
90
From
Degree
To
Radian

90 × π/180 = 1.5708 rad, which is π/2.

Reading the result

  • A full turn is 360 degrees, 2π radians, 400 gradians or 1 turn. A right angle is 90 degrees, π/2 radians or 100 gradians.
  • An arcminute is a sixtieth of a degree and an arcsecond a sixtieth of that, which is the resolution surveying and astronomy work at.

Common mistakes

  • Passing degrees to a trigonometric function. Nearly every programming language expects radians, so sin(30) returns −0.988 instead of 0.5.
  • Confusing this mil with a thousandth of an inch. The angular mil used here is roughly 1/6400 of a turn.

Frequently asked questions

Why use radians?

Trigonometric derivatives and series only take their simple forms in radians. Most programming languages expect radians in their sin and cos functions.

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