How to use the Number Base Converter
- Type a number.
- Choose the base it's written in.
- Read it in every other base.
What does this tool do?
Computers work in binary (base 2), and developers often use hexadecimal (base 16) as a compact way to write binary. Conversions use exact big-integer arithmetic, so even very long numbers convert without rounding.
Why use it?
- Read memory addresses, colors and bit flags.
- Computer science homework.
- Exact for numbers of any size.
Example
255 in decimal is 11111111 in binary, 377 in octal and FF in hexadecimal.
Privacy
Everything you type is processed in your browser. Nothing you enter is sent to our servers or stored by us. There's no account to create and nothing to install.
Frequently asked questions
How do I convert hexadecimal to decimal by hand?
Multiply each digit by a power of 16, starting from the right. FF is 15 × 16 + 15 = 255, and 1A is 1 × 16 + 10 = 26. The letters A–F stand for 10–15.
Why do developers use hexadecimal?
One hex digit represents exactly 4 bits, so a byte is always two hex digits. That makes long binary values much shorter and easier to read — colors like #FF6600 and memory addresses are common examples.
Last reviewed by the M2Toolkit team.