180 Degrees to Radians

180° ≈ 3.1416 rad

= π rad

Calculation: rad = 180° × 0.0174533 ≈ 3.1416 rad

Degree to Radian Converter

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How wide is 180°?

180 degrees is a reflex angle, like the open mouth of a Pac-Man shape.

What does 180° look like?

Illustration of a Pac-Man shape
180 degrees is a reflex angle, like the open mouth of a Pac-Man shape.

Did you know? Straight angle is 180°.

A straight line is 180° — also known as pi radians. The sum of angles in any triangle equals exactly 180°.

How to Convert Degree to Radian

1 degree = 0.0174533 radians exact

Radian = Degree × 0.0174533

Example: 180° × 0.0174533 = 3.1416 rad

Reverse Conversion

To convert radians back to degrees:

  • Remember, 1 radian equals 57.2958 degrees.
  • To convert 3.1416 rad to°, multiply 3.1416 x 57.2958, resulting in 180°.

exact This conversion factor is exact by international definition.

180 ° is also equal to:

About these units

Degree: The degree (°) is a non-SI unit of plane angle defined as 1/360 of a full rotation.It is accepted for use with the SI due to its long-standing practical importance in navigation, surveying, engineeri...

Radian: The radian (rad) is the SI derived unit of plane angle. It is defined as the angle subtended at the center of a circle by an arc equal in length to the radius.Although mathematically dimensionless, th...

Frequently Asked Questions

How much is 180 degrees in radians?

180 degrees equals 3.1416 radians. This is calculated by multiplying 180 by the conversion factor 0.0174533.

What does 180 degrees look like in radians?

180 degrees (3.1416 radians) is a straight angle (180°), forming a perfectly straight line — a half turn.

How do you calculate 180 degrees to radians?

Multiply 180 by the conversion factor 0.0174533. The calculation is 180 × 0.0174533 = 3.1416 radians. This factor is defined by international measurement standards.

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180 degrees = 3.14159 radians
180 degrees = 3.14159 radians — conversion chart

Nearby Conversions

30 degrees0.5236 radians 60 degrees1.047 radians 90 degrees1.571 radians 120 degrees2.094 radians 150 degrees2.618 radians 210 degrees3.665 radians 240 degrees4.189 radians 270 degrees4.712 radians 300 degrees5.236 radians 330 degrees5.76 radians 360 degrees6.283 radians 390 degrees6.807 radians 420 degrees7.33 radians 450 degrees7.854 radians 480 degrees8.378 radians

For general conversions between degrees and radians, see the degrees to radians converter.

Also convert Degrees to:

Conversion factors verified against BIPM, ISO 80000-3 1 turn = 2π rad = 360° (exact, ISO 80000-3). Last reviewed: March 2026
Adilson Fernandes By Adilson Fernandes
Tiago Fernandes Reviewed by Tiago Fernandes

All unit conversions on CoolConversion use conversion factors defined or documented by internationally recognised standards bodies (such as ISO and NIST), including both SI and non-SI units.