How to convert Degrees to radians
rad = ° × π ÷ 180
One full turn is 2π radians or 360 degrees. Keeping π in the formula avoids rounding a decimal conversion factor before calculating the result.
Worked examples
90 ° ≈ 1.570796327 rad
(90) × π ÷ 180 ≈ 1.570796327
180 ° ≈ 3.141592654 rad
(180) × π ÷ 180 ≈ 3.141592654
Frequently asked questions
Why does the formula include π?
A complete turn is 2π radians, equal to 360 degrees or 400 gradians. Keeping π symbolic avoids prematurely rounding the conversion coefficient.