Angle Unit Converter

Degrees to Radians Converter

Convert angles from degrees (°) into radians (rad) instantly with exact Pi (π) fraction notation, step-by-step formula calculations, worked examples, and conversion charts.

Quick Summary: How to Convert Degrees to Radians

To convert any angle from Degrees (°) to Radians (rad), multiply the angle in degrees by π / 180:
Angle in Radians = Angle in Degrees × (π / 180)
Example: $180^\circ = \pi \text{ rad} \approx 3.141593 \text{ rad}$, and $90^\circ = \frac{\pi}{2} \text{ rad} \approx 1.570796 \text{ rad}$.

Standard Angles:
π / 2 rad
1.570796 rad
90° = 1.570796 radians
Formula: 90° × (π / 180) = 90π / 180 = π / 2 rad ≈ 1.570796 rad

Degrees to Radians Conversion Chart

Standard trigonometry reference table showing common angles in degrees, exact Pi (π) fraction notation, and decimal radian equivalents:

Degrees (°)Exact Pi (π) RadiansDecimal Radians (rad)Action
0°0 rad0 rad
30°π / 6 rad0.523599 rad
45°π / 4 rad0.785398 rad
60°π / 3 rad1.047198 rad
90°π / 2 rad1.570796 rad
120°2π / 3 rad2.094395 rad
135°3π / 4 rad2.356194 rad
150°5π / 6 rad2.617994 rad
180°π rad3.141593 rad
210°7π / 6 rad3.665191 rad
225°5π / 4 rad3.926991 rad
240°4π / 3 rad4.188790 rad
270°3π / 2 rad4.712389 rad
300°5π / 3 rad5.235988 rad
315°7π / 4 rad5.497787 rad
330°11π / 6 rad5.759587 rad
360°2π rad6.283185 rad

How to Convert Degrees to Radians (Step-by-Step)

A degree (°) is a unit of angle measurement defined such that a full circle revolution contains 360 degrees. A radian (rad) is the SI unit of angle measure defined as the angle subtended at the center of a circle by an arc whose length is equal to the radius of the circle. A full circle revolution equals 2π radians.

The Fundamental Relation:

Since $360^\circ = 2\pi \text{ radians}$, dividing both sides by 2 gives:
180° = π radians

Conversion Formula:

To convert any angle from degrees to radians, multiply by π / 180:
Radians = Degrees × (π / 180)

Worked Step-by-Step Examples:

Example 1: Convert 45° to Radians
  1. Multiply 45 by π / 180: 45 × (π/180)
  2. Simplify fraction 45/180: 45/180 = 1/4
  3. Exact result: π / 4 rad
  4. Decimal result: 0.785398 rad
Example 2: Convert 120° to Radians
  1. Multiply 120 by π / 180: 120 × (π/180)
  2. Simplify fraction 120/180: 120/180 = 2/3
  3. Exact result: 2π / 3 rad
  4. Decimal result: 2.094395 rad
Example 3: Convert 270° to Radians
  1. Multiply 270 by π / 180: 270 × (π/180)
  2. Simplify fraction 270/180: 270/180 = 3/2
  3. Exact result: 3π / 2 rad
  4. Decimal result: 4.712389 rad
Example 4: Convert 360° to Radians
  1. Multiply 360 by π / 180: 360 × (π/180)
  2. Simplify fraction 360/180: 360/180 = 2
  3. Exact result: 2π rad
  4. Decimal result: 6.283185 rad

Reverse Conversion: How to Convert Radians to Degrees

To convert radians back into degrees, multiply the angle in radians by 180 / π:

Radians to Degrees Formula:
Degrees = Radians × (180 / π)

Example: Convert π / 3 radians to degrees:
(π/3) × (180/π) = 180 / 3 = 60°.

Popular Angle Unit Conversions

Explore popular angle measurement conversion tools and reference calculators:

Convert Degrees to Other Angle Units

Quick conversion options from Degrees (°) to all standard angular measurement units:

Angle Unit Conversion Formula Matrix

Degrees to Radians
rad = deg × (π / 180)
1° ≈ 0.0174533 rad
Radians to Degrees
deg = rad × (180 / π)
1 rad ≈ 57.29578°
Degrees to Gradians
grad = deg × (10 / 9)
90° = 100 gon

How to Use the Degrees to Radians Tool in 4 Steps

1
Input Degrees

Type your angle in degrees into the input field or click a standard preset chip.

2
Auto-Calculate

The converter instantly calculates the exact Pi fraction and decimal radian values.

3
View Formula Step

Check the dynamic formula breakdown explaining the exact simplification.

4
Copy Result

Click the Copy button to quickly copy the formatted output for your work.

Frequently Asked Questions (FAQs)

To convert degrees to radians, multiply the angle in degrees by π / 180. For example, 180 degrees equals 180 × (π/180) = π radians.

180 degrees is exactly equal to π radians (≈ 3.14159265 radians).

1 degree is equal to π / 180 radians, which is approximately 0.0174533 radians.

A complete circle revolution contains 360 degrees or 2π radians. Simplifying the conversion factor ratio 2π / 360 gives π / 180.