Radian ↔ Degree Converter
Instant Angle Conversion ⚡

Convert any angle between radians and degrees instantly. Enter either value and the other is calculated immediately.

Common Angles

Conversion Formulas

Degrees to Radians: radians = degrees × π ÷ 180

Radians to Degrees: degrees = radians × 180 ÷ π

One full circle = 360° = 2π radians. A right angle = 90° = π/2 radians.

Common Angle Reference Table

Degrees Radians (exact) Decimal
00
30°π/60.5236
45°π/40.7854
60°π/31.0472
90°π/21.5708
180°π3.1416
270°3π/24.7124
360°6.2832

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Frequently Asked Questions

Why do we use radians?
Radians are the natural unit for angles in mathematics because they simplify calculus formulas. The derivative of sin(x) is cos(x) only when x is in radians. Degrees are more intuitive for everyday use, but radians are essential in higher maths.

What is π?
Pi (π) is approximately 3.14159265. It is the ratio of a circle's circumference to its diameter, and appears throughout mathematics. One radian is the angle subtended at the centre of a circle by an arc equal in length to the radius.

When do I need radians vs degrees?
Use degrees for everyday angles, bearings, and basic trigonometry. Use radians in calculus, physics, engineering, and when using most programming languages' built-in trig functions (which expect radians by default).

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