Number Base Converter

About this calculator

This tool converts a number between the four bases most commonly used in computing and mathematics — binary (base 2), octal (base 8), decimal (base 10) and hexadecimal (base 16) — by interpreting the input in its source base and re-expressing the same value using each target base's digit set. Binary uses only 0 and 1, hex extends beyond 9 into the letters A–F, and the calculator handles the underlying place-value math automatically in either direction.

Programmers and computer science students use base conversion constantly, since computers store data in binary at the hardware level but binary numbers become unreadably long, so hexadecimal is used as compact shorthand in memory addresses, color codes and low-level debugging, while octal still appears in older systems and file permission notation. Anyone learning how computers represent numbers internally, or needing to manually check a hex or binary value against its decimal equivalent, relies on a converter like this rather than doing the place-value arithmetic by hand.