Skip to content
UnitCalculators.com

Radians to gradians

Multiply radians by 63.662 to get gradians.

1 rad = 63.662 gonBIPM SI
rad
190.9859gon

3 rad = 190.9859 gon

How to convert radians to gradians

The gradian is one 400th of a full turn — used in surveying. The radian is the SI angle unit — the angle subtending an arc equal to the radius; a full turn is 2π rad.

Worked example — 3 rad: 3 × 63.662 = 190.9859 gon.

Radians to gradians table

Common conversions.
RadiansGradians
0.5 rad31.831 gon
1 rad63.662 gon
1.5708 rad100.0002 gon
2 rad127.324 gon
3 rad190.9859 gon
3.1416 rad200.0005 gon
4 rad254.6479 gon
5 rad318.3099 gon
6.2832 rad400.0009 gon

Reverse and related

About radians and gradians

Radian (rad)

1 rad = 63.662 gon

Definition. The SI angle unit — the angle subtending an arc equal to the radius; a full turn is 2π rad

History and origin

The radian is the natural mathematical measure of angle, the angle that cuts off an arc equal to the radius, so a full turn is 2π radians. The idea dates to the eighteenth century and the name was adopted in the 1870s.

Current use

Radians are used in trigonometry, physics and programming, where they make the mathematics of rotation simplest.

Source: BIPM SI Brochure (2019); ISO 80000-3 (angle)

Gradian (gon)

1 gon = 0.015708 rad

Definition. One 400th of a full turn — used in surveying

History and origin

The gradian, or gon, divides the right angle into 100 parts, giving 400 to a full turn. It was introduced in France alongside the metric system to decimalise angle measure.

Current use

Gradians are used in surveying and some European engineering.

Source: BIPM SI Brochure (2019); ISO 80000-3 (angle)

Where people use this

Radians: trigonometry, physics, programming. Gradians: surveying, some European engineering. π radians is exactly 200 gradians.

How we know this is right
The factor is fixed by the standards that define the units, not chosen — so it is exact, not a measurement:
1 gon = 0.01570796327 rad, so 1 rad = 1 ÷ 0.01570796327 = 63.662 gon.

Every value is carried to full double precision; the display is rounded.

Both units are defined in BIPM SI Brochure (2019); ISO 80000-3 (angle).

Questions people ask

How many gradians is π radians?

π radians is exactly 200 gradians.

How many gradians in a radian?

One radian is about 63.66 gradians.

How many gradians is 2π radians?

A full turn, 2π radians, is 400 gradians.

All radian conversions