Straight angle
Input: 180°
Output: 3.141593 rad
180 × π/180 = π ≈ 3.141593 radians.
degrees to radians converter
Use this for trigonometry and code that expects angles in radians.
Radians:
Formula and algorithm
- radians = degrees × π / 180
- π ≈ 3.14159265358979; a full circle (360°) is 2π radians.
- Multiply the degree value by π/180 ≈ 0.0174533 to get radians.
Worked examples
Right angle
Input: 90°
Output: 1.570796 rad
90 × π/180 = π/2 ≈ 1.570796 radians.
Eighth turn
Input: 45°
Output: 0.785398 rad
45 × π/180 = π/4 ≈ 0.785398 radians.
FAQ
What is 180 degrees in radians?
Exactly π radians, about 3.141593.
Why π/180?
A full circle is 360° and also 2π radians, so 1° = 2π/360 = π/180 radians.
Do trig functions in code use radians?
Most do (e.g. JavaScript Math.sin), so convert degrees to radians first.
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Updated: June 7, 2026