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UnitCalculators.com

Degrees to radians

Multiply degrees by 0.0174533 to get radians.

1 ° = 0.0174533 radBIPM SI
°
1.0472rad

60 ° = 1.0472 rad

How to convert degrees to radians

The radian is the SI angle unit — the angle subtending an arc equal to the radius; a full turn is 2π rad. The degree is one 360th of a full turn — the everyday unit of angle.

Worked example — 60 °: 60 × 0.0174533 = 1.0472 rad.

Degrees to radians table

Common conversions. The reverse table is on radians to degrees.
DegreesRadians
1 °0.0174533 rad
15 °0.261799 rad
30 °0.523599 rad
45 °0.785398 rad
60 °1.0472 rad
90 °1.5708 rad
120 °2.0944 rad
180 °3.1416 rad
360 °6.2832 rad

Reverse and related

About degrees and radians

Degree (°)

1 ° = 0.0174533 rad

Definition. One 360th of a full turn — the everyday unit of angle

History and origin

The degree, one 360th of a full turn, goes back to ancient Babylonian astronomers, whose base-60 counting made 360 a natural division of the circle. It has been the everyday angle measure ever since.

Current use

Degrees are used in geometry, navigation and construction, wherever angles are set out or read off.

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

Radian (rad)

1 rad = 57.2958 °

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)

Where people use this

Degrees: geometry, navigation, construction angles. Radians: trigonometry, physics, programming. 180° is exactly π radians.

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 rad = 57.29577951 °, so 1 ° = 1 ÷ 57.29577951 = 0.0174533 rad.

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 radians is 180 degrees?

180° is exactly π radians (about 3.1416). To convert degrees to radians, multiply by π/180.

How do you convert degrees to radians?

Multiply the degrees by π/180, so 90° is π/2, about 1.571 radians, and 45° is π/4.

How many radians is 360 degrees?

A full turn, 360°, is 2π radians (about 6.283).

How many radians is 1 degree?

One degree is π/180 radians, about 0.01745 radians.

All degree conversions