角度转换器

常见问题

›How do I convert degrees to radians?

Multiply degrees by π/180 (≈ 0.01745). So 90° = π/2 ≈ 1.5708 rad. Or just type it here.

›What's a gradian?

A gradian (or 'gon') is 1/400 of a full circle. Used by surveyors so that a right angle is exactly 100 gon — easier mental math.

›Why use radians instead of degrees?

Because 1 radian is the angle that makes the arc length equal to the radius — calculus formulas (sin, cos derivatives) only work cleanly in radians.

›Is the converter free?

Yes — free, no signup, runs in your browser.

›How precise is it?

Double-precision (15+ significant digits) — exact to whatever precision your calculation needs.