Radian to Degree Converter

Q: What is pi radians in degrees?

Pi radians equals exactly 180 degrees. This is because pi radians represents half of a full circle (360 degrees). Similarly, 2pi radians equals 360 degrees (a full circle).

Convert radians to degrees instantly with interactive unit circle diagram, step-by-step calculation, common angle reference, DMS output, and batch conversion. Free online angle converter for math, physics, and engineering.

Free to useNo sign-up requiredUpdated Jan 2026

Radian to Degree ConverterTry it now — free ▼

Embed Radian to Degree Converter Widget

Conversion Result

Quadrant II (90° to 180°)

pi/2

radians

90.000000°

degrees

DMS: 90° 0' 0.0"

Reference: 90.0°

Normalized: 90.0°

Unit Circle Position

90.000000°

Degrees

1.5707963268

Radians (decimal)

90° 0'

DMS Format

Quadrant

Trigonometric Values

sin(pi/2)

1.0

cos(pi/2)

-0.0

tan(pi/2)

undefined

Step-by-Step Calculation

Identify the Input Value

The input angle in radians is: pi/2

Input = pi/2 radians

Convert Pi Notation to Decimal

Using π ≈ 3.14159265358979...

pi/2 ≈ 1.5707963268 radians

3
Apply Conversion Formula
Multiply radians by 180/π to get degrees
Degrees = Radians × (180° / π)

Substitute Values

Replace values in the formula

Degrees = 1.5707963268 × (180° / π)

5
Calculate Result
Perform the multiplication
Degrees = 1.5707963268 × 57.2957795... = 90.000000°

Common Angle Reference

Conversion Formula

Degrees = Radians × (180° / π) ≈ Radians × 57.2958

About Radian to Degree Converter

The Radian to Degree Converter is a powerful tool for converting angle measurements from radians to degrees. It supports multiple input formats including decimal values, pi notation (pi/2, 2pi, 3pi/4), and provides comprehensive results including DMS format, unit circle visualization, quadrant identification, and step-by-step calculations.

How to Convert Radians to Degrees

Converting radians to degrees uses the fundamental relationship between these two angle measurement systems. Since a full circle contains $2\pi$ radians and 360 degrees, we can derive the conversion formula.

Degrees = Radians × $\frac{180°}{\pi}$

The conversion factor $\frac{180}{\pi}$ equals approximately 57.2957795131. This means:

1 radian ≈ 57.2958 degrees
π radians = 180 degrees (exactly)
2π radians = 360 degrees (a full circle)

The Radian to Degree Conversion Formula

The formula for converting radians to degrees is derived from the definition of a radian:

Formula: $\text{Degrees} = \text{Radians} \times \frac{180°}{\pi}$

Example: Convert $\frac{\pi}{4}$ radians to degrees

$\frac{\pi}{4} \times \frac{180°}{\pi} = \frac{180°}{4} = 45°$

How to Use This Converter

Enter the radian value: Type your angle in radians. You can use decimal format (1.5708), pi notation (pi/2, 2pi), or fractions of pi (3pi/4).
Set precision: Choose how many decimal places you want in the result (0-15).
Click Convert: Press the button to perform the conversion.
View results: See the degree value along with DMS format, quadrant, unit circle position, and trigonometric values.
Review steps: Examine the step-by-step calculation to understand the conversion process.

Common Radian to Degree Conversions

Radians	Degrees	Description
0	0°	Zero angle
π/6	30°	One-twelfth of a circle
π/4	45°	One-eighth of a circle
π/3	60°	One-sixth of a circle
π/2	90°	Quarter turn (right angle)
2π/3	120°	One-third of a circle
3π/4	135°	Three-eighths of a circle
π	180°	Half turn (straight angle)
3π/2	270°	Three-quarter turn
2π	360°	Full turn (complete circle)

What is a Radian?

A radian is the standard unit of angular measure in mathematics. One radian is defined as the angle subtended at the center of a circle by an arc whose length equals the radius of the circle.

Key facts about radians:
A full circle contains $2\pi$ radians (approximately 6.283 radians)
A semicircle (half turn) contains $\pi$ radians
A right angle is $\frac{\pi}{2}$ radians
Radians are dimensionless (the ratio of arc length to radius)

Why Use Radians?

Radians are preferred in mathematics and physics because they simplify many formulas:

Calculus: The derivatives of trigonometric functions are simpler in radians. For example, $\frac{d}{dx}\sin(x) = \cos(x)$ only when x is in radians.
Arc length: Arc length = radius × angle (in radians). No conversion factor needed.
Angular velocity: Physics uses radians per second as the standard unit.
Series expansions: Taylor series for trig functions assume radian measure.

Understanding the Unit Circle

The unit circle is a circle with radius 1 centered at the origin. It provides a visual way to understand angle measurements and trigonometric functions:

Quadrant I (0° to 90°): Both sine and cosine are positive
Quadrant II (90° to 180°): Sine positive, cosine negative
Quadrant III (180° to 270°): Both sine and cosine are negative
Quadrant IV (270° to 360°): Sine negative, cosine positive

Frequently Asked Questions

How do I convert radians to degrees?

To convert radians to degrees, multiply the radian value by 180/π (approximately 57.2958). The formula is: degrees = radians × (180/π). For example, π/2 radians = (π/2) × (180/π) = 90 degrees.

What is the formula for radian to degree conversion?

The radian to degree conversion formula is: Degrees = Radians × (180/π). Since 180/π is approximately 57.2957795131, you can also use: Degrees = Radians × 57.2957795131.

What is pi radians in degrees?

Pi radians equals exactly 180 degrees. This is because π radians represents half of a full circle (360 degrees). Similarly, 2π radians equals 360 degrees (a full circle).

Why do we use radians instead of degrees?

Radians are the natural unit for angle measurement in mathematics and physics because they simplify many formulas. In calculus, derivatives of trigonometric functions are simpler when angles are in radians. One radian is the angle where the arc length equals the radius.

How many degrees are in 1 radian?

One radian equals approximately 57.2957795131 degrees. This is calculated as 180/π. Conversely, 1 degree equals approximately 0.0174533 radians (π/180).

Reference this content, page, or tool as:

"Radian to Degree Converter" at https://MiniWebtool.com/radian-to-degree-converter/ from MiniWebtool, https://MiniWebtool.com/

by miniwebtool team. Updated: Jan 11, 2026

Developer API available: Run this tool from your app, automation, or agent with one JSON HTTP request. View API docs

You can also try our AI Math Solver GPT to solve your math problems through natural language question and answer.