EasyUnitConverter.com

Circle to Radian Converter

Enter the value that you want to convert circle (cir) to radian (rad) or radian to circle.Also written as CIR to RAD conversion.

1 circle = 6.2831853 radian

Formula: radian = circle value × 6.2831853

CIR to RADcircle to radian

cir
62.83185rad

10 circle = 62.83185 radian

Popular Degree Converters:

Circle vs Radian

What is Circle?

The circle as an angular unit represents one complete revolution of 360°.

Used primarily in rotational mechanics and angular displacement, counting in "circles" simplifies problems involving multiple rotations. Wind turbine specifications, satellite orbits, and gear train calculations often express total angular displacement in full circles rather than degrees.

The Radian: History & Usage

The radian is defined as the angle subtended at the center of a circle by an arc equal in length to the radius.

Adopted as the SI unit of angular measure, the radian makes calculus and physics equations significantly simpler because it eliminates conversion constants. One full revolution equals 2π radians (≈ 6.2832 rad). Radians are essential in signal processing, robotics, computer graphics (3D rotations), oscillation analysis, and any domain where angular velocity or frequency calculations are performed.

Why Angle Conversions Matter

Angle conversions bridge the gap between everyday measurement (degrees) and mathematical computation (radians). A mechanical engineer designing a robotic arm needs radians for inverse kinematics. A pilot reads compass headings in degrees. A surveyor might work in gradians. Game developers convert between degrees (artist-friendly) and radians (GPU shaders) hundreds of times per frame. Understanding these conversions is essential across STEM fields, navigation, and digital media production.

circle to radian metric conversion table

0.01 cir=0.06283 rad
0.1 cir=0.62832 rad
1 cir=6.28319 rad
2 cir=12.56637 rad
3 cir=18.84956 rad
4 cir=25.13274 rad
5 cir=31.41593 rad
6 cir=37.69911 rad
7 cir=43.98230 rad
8 cir=50.26548 rad
9 cir=56.54867 rad
10 cir=62.83185 rad
11 cir=69.11504 rad
12 cir=75.39822 rad
13 cir=81.68141 rad
14 cir=87.96459 rad
15 cir=94.24778 rad
16 cir=100.53096 rad
17 cir=106.81415 rad
18 cir=113.09734 rad
19 cir=119.38052 rad
20 cir=125.66371 rad
30 cir=188.49556 rad
40 cir=251.32741 rad
50 cir=314.15927 rad
60 cir=376.99112 rad
70 cir=439.82297 rad
80 cir=502.65482 rad
90 cir=565.48668 rad
100 cir=628.31853 rad
200 cir=1256.63706 rad
300 cir=1884.95559 rad
400 cir=2513.27412 rad
500 cir=3141.59265 rad
600 cir=3769.91118 rad
700 cir=4398.22972 rad
800 cir=5026.54825 rad
900 cir=5654.86678 rad
1000 cir=6283.18531 rad

How to Convert CIR to RAD (Circle to Radian)?

We can convert circle to radian by using an example.

Example:

Convert 20 Circle to Radian?

We know 1 Circle = 6.2831853 radian; 1 Radian = 0.1591549 circle.

20 circle = ___rad

20 × 6.2831853 = 125.66371 rad (we know 1 circle = 6.2831853 radian)

Answer:

20 circle = 125.66371 radian

Converting Circles to Radians

One circle equals 2π radians (≈ 6.2832). To convert:

  1. Write down the number of circles.
  2. Multiply by 2π (≈ 6.2832).
  3. The result is the angle in radians.
💡 Tip: For whole circles, results are always multiples of 2π: 1 circle = 2π, 2 circles = 4π, etc.

Solved Examples

Question 1: Convert 3 circles to radians.

Solution:

Radians = 3 × 2π

= 6π

≈ 18.85 rad

Answer: 3 circles = 6π ≈ 18.85 radians

Question 2: A flywheel rotates 0.5 circles. Express in radians.

Solution:

Radians = 0.5 × 2π

= π

≈ 3.1416 rad

Answer: 0.5 circles = π radians

Question 3: Angular displacement of 2.25 circles in radians?

Solution:

Radians = 2.25 × 2π

= 4.5π

≈ 14.14 rad

Answer: 2.25 circles = 4.5π ≈ 14.14 radians

Practice Questions

Try solving these on your own to test your understanding:

  1. Convert 10 circles to radians. (Answer: 20π ≈ 62.83 rad)
  2. A motor makes 0.25 circles. Radians? (Answer: π/2 ≈ 1.571 rad)
  3. Express 1.5 circles in radians. (Answer: 3π ≈ 9.425 rad)

Frequency and Angular Velocity

Frequency (f) in Hz means circles per second. Angular velocity (ω) in rad/s = f × 2π. A 60 Hz power supply completes 60 circles per second = 120π ≈ 377 rad/s. This relationship ω = 2πf is fundamental in electrical engineering, wave physics, and signal processing.

Key Takeaways

  • Multiply circles by 2π (≈ 6.2832) to get radians.
  • ω = 2πf converts frequency (circles/s) to angular velocity (rad/s).
  • 1 circle = 2π rad = 360° = 400 gon.

Circle to Radian Conversion Formula

radian = circle × 6.2831853

1 circle = 6.2831853 radian

1 radian = 0.1591549 circle

Reverse: circle = radian × 0.1591549

Frequently Asked Questions

How many radian are in 1 circle?

There are 6.2831853 radian in 1 circle. To convert circle to radian, multiply the value by 6.2831853.

How do I convert circle to radian?

Multiply your circle value by 6.2831853 to get the equivalent in radian. For example, 5 circle = 5 × 6.2831853 = 31.41593 radian.

How do I convert radian to circle?

Multiply your radian value by 0.1591549 to get the equivalent in circle. Alternatively, divide by 6.2831853.

What is 10 circle in radian?

10 circle is equal to 62.83185 radian.

What is 100 circle in radian?

100 circle is equal to 628.31853 radian.