Angle converter

Four: deg, rad, grad and turn. Degrees are the base unit. A radian is 57.29577951308232 degrees, a gradian is 0.9 degrees, so a right angle is 100 grad, and a turn is 360 degrees, one full circle. You choose both the from and to units, since neither has a default.

The factor is 57.29577951308232, which is 180 divided by pi to the full precision a JavaScript number holds. Converting 180 deg to rad lands close to pi but not on a symbolic pi, because the arithmetic is binary floating point. For trigonometry, pass radians straight into the function rather than round-tripping them through here.

One hundredth of a right angle, 0.9 degrees, so 100 grad is 90 degrees and 400 grad is a full circle. It turns up in surveying and on calculators, often labeled gon or grade. If a calculator is giving you unexpected trig answers, check whether it is sitting in grad mode.

One full revolution, 360 degrees. It is convenient for rotation in CSS and animation, where 0.25turn is a quarter circle and 2turn is two full spins. Fractions are fine: enter 0.125 and convert to deg to get 45, or convert 90 deg to turn to get a quarter. Negative values work the same way, for a rotation the other direction.

Not here. This converter takes a single decimal number, so 40 degrees 42 minutes 46 seconds has to become a decimal first. The coordinate format converter does that for latitude and longitude, printing DD, DMS or UTM. For a plain angle, divide the minutes by 60 and the seconds by 3600 and add them to the degrees.