Binary to Hex Converter
Convert binary to hexadecimal — four binary digits make exactly one hex digit, which is why the two go together so neatly.
Hexadecimal exists because binary is unreadable at length.
How the binary to hex converter works
Hexadecimal exists because binary is unreadable at length. Sixteen is two to the fourth, so every group of four bits maps to exactly one hex digit with no arithmetic: 1111 is F, 1010 is A, 0000 is 0.
That is the whole trick. Split the binary into four-bit groups from the right, pad the leftmost group with zeros, and translate each group independently. A 32-bit value becomes eight hex digits, which a person can actually read aloud.
Formula: value = Σ digitₖ × bᵏ
Worked examples
| Inputs | Converted | Note |
|---|---|---|
| 11111111 | FF | FF |
| 1010 | A | A |
| A byte with a high bit | 80 | 80 |
FAQFrequently asked questions
How do I convert binary to hex?
Group the bits in fours from the right and translate each group: 1111 is F, 1010 is A.
Why four bits per hex digit?
Because 16 is 2⁴, so four bits express exactly the sixteen hex values with nothing left over.
What is 11111111 in hex?
FF, which is 255 in decimal — the largest value a byte holds.
Why use hex at all?
Because it is compact and maps cleanly to binary. FF is far easier to read and say than 11111111.
What if the bits do not divide by four?
Pad the leftmost group with zeros. 101 becomes 0101, which is 5.
Where these figures come from
- NIST Digital Library of Mathematical Functions — reference definitions for elementary and special functions
- Wolfram MathWorld — definitions and formulas for every topic on this page
- NIST/SEMATECH e-Handbook of Statistical Methods — the statistical formulas (mean, variance, z, confidence intervals, sample size)
- National curriculum in England — Mathematics — the terms and methods taught in UK schools
Last checked: September 2026. Formulas are fixed by mathematics and do not change with tax years or regulations.