Why this site exists
Converting between number bases is simple maths, but it is easy to slip up when a value has eight or sixteen digits. Most converters give you an answer and nothing else. We wanted one that also shows how the answer was reached, so you can trust it, check it and learn from it.
What it does
- Converts decimal to hexadecimal and back, and between decimal, hexadecimal, binary and octal in any direction.
- Shows the working: each digit times its power for one direction, repeated division for the other.
- Gives exact results for any size. 64-bit and 128-bit values convert with every digit correct.
- Accepts values the way you write them:
0xFF,#FF,FFh, with spaces or underscores.
Who it is for
Programmers reading memory addresses, error codes and bit masks. Students learning number systems in computer science, electronics and networking. Anyone who needs a quick, reliable conversion without signing up for anything.
Private by design
Every conversion runs in your browser. There are no accounts, no tracking and no adverts, and the numbers you type are never sent to a server. You can read the details in our privacy policy.
Have a suggestion or found a mistake? We would love to hear from you.