CalcWhenHexadecimal Converter
255 in hexadecimal is FF — the largest two-digit hex value, which is exactly why full-strength colour channels in #RRGGBB codes end in FF.
How it works
Hexadecimal is decimal's compact cousin: sixteen digits (0–9, then A–F) that map cleanly onto binary, four bits at a time. Convert either way here, with the 0x-prefixed form programmers write, plus binary and octal for the full picture.
If you arrived from colour codes: a #RRGGBB code is three hex numbers side by side, one per channel — convert each pair separately to get its 0–255 value.
The method
Base-16 conversion on whole numbers. Hex input is validated to digits 0–9 and letters A–F (any case, optional 0x prefix stripped) before parsing positionally.
Frequently asked questions
Why do hex digits include letters?
Base 16 needs sixteen distinct digits; after 9, the convention borrows A=10 through F=15. So FF = 15×16 + 15 = 255.
What does 0x mean?
A prefix programmers put in front of hex numbers in code (0xFF) so parsers — and readers — know the base. It carries no value itself.
How do I convert a colour like #1E90FF?
Split it into pairs — 1E, 90, FF — and convert each: 30, 144, 255, the red, green and blue channel strengths.