Last updated 26 August 2026
What "base" means
A number base is how many distinct digits a system uses before carrying to a new place value. Decimal (base 10, what people use day to day) has digits 0-9. Binary (base 2) has only 0 and 1 — the language computer hardware actually runs on. Hexadecimal (base 16) adds A-F to 0-9, giving a much more compact way to represent the same binary values, which is why it shows up constantly in programming, color codes and memory addresses.
Common questions
What is a number base?
It's how many distinct digits a counting system uses before it carries over to a new place value. Decimal (base 10) uses 0-9, binary (base 2) uses only 0 and 1, octal (base 8) uses 0-7, and hexadecimal (base 16) uses 0-9 plus A-F.
Why does programming use hex and binary at all?
Computers store everything as binary at the hardware level, but long strings of 1s and 0s are hard for people to read. Hexadecimal compresses that same binary value into a much shorter, easier-to-scan form — which is why colors, memory addresses and byte values are usually shown in hex.
Can I enter negative numbers?
No — this tool works with non-negative whole numbers only, which covers the large majority of everyday binary/hex conversion needs like color codes and byte values.