Angle Unit Info

Common angle units:

  • Degree (°): most widely used
  • Radian (rad): used in mathematics
  • Gradian (grad): used in surveying
  • Mil: used in military applications

Key relationships:

  • 360° = 2π rad = 400 grad = 6400 mils
  • 1 rad ≈ 57.2958°
  • 1° = π/180 rad ≈ 0.01745 rad

Degrees:

The degree measurement originates from ancient Babylonian astronomy, which used a sexagesimal (base-60) system. The division of a circle into 360 parts may relate to the approximate number of days in a year.

Radians:

Introduced in the 18th century, the radian is considered the natural unit for measuring angles in mathematics. It represents the angle subtended by an arc whose length equals the radius of the circle.

Gradians:

Developed during the French Revolution as part of the metric system, dividing a circle into 400 equal parts (100 gradians in a right angle).

Degrees are used for:

  • Navigation and mapping
  • Everyday angle measurements
  • Geography (latitude/longitude)
  • Weather and wind direction

Radians are used for:

  • Calculus and advanced mathematics
  • Physics (angular velocity/momentum)
  • Engineering calculations
  • Signal processing

Other units:

  • Gradians: surveying and engineering
  • Mils: military artillery and targeting
  • RPM: rotational speed in machinery

Angle Unit Conversion Calculator

Conversion Result

1 =
1.000

Use the converter above to calculate different values and units

What are Angle Measurements?

Angle measurements quantify the amount of rotation between two intersecting lines or planes. There are several systems for measuring angles, with degrees, radians, and gradians being the most common.

The relationship between these units is precisely defined: 360 degrees (°) = 2π radians (rad) = 400 gradians (grad) = 1 revolution (rev). This relationship is fundamental to trigonometry, calculus, physics, engineering, navigation, and many other fields.

Learn more from NIST or Bureau International des Poids et Mesures (BIPM).

Common Angle Conversions

AngleDegrees (°)Radians (rad)Gradians (grad)
Right angle90°π/2 rad (≈ 1.5708)100 grad
Straight angle180°π rad (≈ 3.1416)200 grad
Full circle360°2π rad (≈ 6.2832)400 grad
1 radian57.2958°1 rad63.662 grad
30° (π/6)30°π/6 rad (≈ 0.5236)33.333 grad
45° (π/4)45°π/4 rad (≈ 0.7854)50 grad
60° (π/3)60°π/3 rad (≈ 1.0472)66.667 grad

Angular Velocity Conversions

Angular VelocityDegrees/second (°/s)Radians/second (rad/s)RPM
1 RPM6 °/s0.1047 rad/s1 RPM
1 rad/s57.2958 °/s1 rad/s9.5493 RPM
60 RPM360 °/s6.2832 rad/s60 RPM

Practical Applications of Angle Conversions

Mathematics & Education

  • Converting between degrees and radians for trigonometric calculations
  • Teaching students different angle measurement systems
  • Solving geometric problems in different coordinate systems

Physics & Engineering

  • Calculating rotational motion in physics (using radians for angular velocity)
  • Engineering analysis of rotating machinery (using RPM and rad/s)
  • Robotics and automation for precise angular positioning
  • Optics and wave mechanics calculations

Navigation & Geography

  • Maritime and aviation navigation using degrees, minutes, and seconds
  • GPS coordinates and mapping systems
  • Surveying and land measurement (using gradians)

Military & Defense

  • Artillery targeting using military angular mil measurements
  • Ballistics calculations requiring precise angle conversions
  • Radar and sensor operations

Astronomy & Space

  • Celestial navigation and star mapping
  • Telescope positioning and tracking
  • Orbital mechanics calculations

Educational Resource

This educational video from Khan Academy explains how to convert between degrees and radians, with clear examples and visual demonstrations of the mathematical relationships.

Angle Conversion Resources

Download Angle Conversion Chart (PDF)

Get our comprehensive angle conversion chart showing degrees, radians, gradians, and other angle units for quick reference when you're working with trigonometry and angular measurements.

Angle Conversion FAQs

Find answers to common questions about angle measurements and conversions.