Degrees vs Radians Explained

Use degrees for most school problems unless your question says radians or uses π. Type sin(30). If you get 0.5, you're in degrees (DEG). If you get about −0.988, you're in radians (RAD).

The 5-second test

1. Open the calculator and note whether DEG or RAD is highlighted.
2. Enter sin(30) and press Enter.
3. 0.5 means DEG. A value near −0.988 means RAD.

On CalcSolver, use the DEG / RAD toggle above the keypad. The current mode stays highlighted.

How to convert

Multiply degrees by π and divide by 180. So 30° is 0.5236 radians (that's π/6), and 180° is π, about 3.1416.

• degrees → radians: radians = degrees × π ÷ 180
• radians → degrees: degrees = radians × 180 ÷ π

Example: 1 radian ≈ 57.30°.

Picture it on the unit circle

When each mode shows up in problems

• Degrees — geometry angles, most textbook trig tables, “sin 30° = 1/2.”
• Radians — calculus, many physics formulas, and any angle written with π (like π/6).

For more key mistakes (log vs ln, brackets on roots), see How to use a scientific calculator.