What units are supported?

Degrees (°), radians (rad), and gradians (gon). 360° = 2π rad = 400 gon. Enter a value in any unit and the others update.

Gradians (or gon) divide a right angle into 100. So 90° = 100 gon. Used in some surveying and engineering contexts.

Online Angle Converter

Convert between degrees, radians, and gradians. Enter an angle in one unit and see the equivalent in the others. Client-side only.

Unit of inputAngle value

What units are supported?: Degrees (°), radians (rad), and gradians (gon). 360° = 2π rad = 400 gon. Enter a value in any unit and the others update.
What are gradians?: Gradians (or gon) divide a right angle into 100. So 90° = 100 gon. Used in some surveying and engineering contexts.

Celsius to Fahrenheit Converter

Convert Celsius to Fahrenheit and Fahrenheit to Celsius instantly. Free temperature converter.

Tip Calculator

Calculate tip and split the bill. Enter bill amount, tip percentage, and number of people.

Roman Numeral Converter

Convert numbers to Roman numerals and Roman numerals to numbers. Supports 1–3999.

Combinations Calculator

Calculate C(n,r) — the number of ways to choose r items from n without order. Uses n!/(r!(n-r)!).

Combinations with Replacement Calculator

Calculate the number of ways to choose r items from n with repetition allowed. Formula: C(n+r-1, r).

Even Permutations Calculator

Count how many permutations of n objects are even (expressible as an even number of swaps). For n ≥ 2, equals n!/2.