How to Use the Angle Unit Converter
Angles are expressed in different units depending on the field. Everyday use and most engineering drawings use degrees (°), but trigonometric functions in programming languages like sin() and cos() almost always expect radians (rad). Gradians (grad) are used in surveying and some European engineering contexts, where a right angle equals 100 grad.
Enter a value, select its unit, and instantly see the equivalent in degrees, radians, and gradians. Radians are based on π, following the relationship 360° = 2π rad = 400 grad.
Use this tool to get the radian value for Math.sin() or Math.cos() in code, convert CAD or surveying data between unit systems, or calculate rotation angles for animations. For reference, 90° equals exactly π/2 rad (about 1.5708 rad) and 100 grad.
Frequently Asked Questions
A radian is defined by the ratio of an arc length to the radius of a circle, which simplifies trigonometric formulas in math, physics, and programming. Most programming languages require radians as input for trig functions like sin() and cos().
Gradians (grad) are a decimal-based angle unit where a right angle equals 100 grad. They're mainly used in surveying and civil engineering in some European countries, and on certain scientific calculators.