Number Base Converter
Convert between binary, octal, decimal, and hexadecimal instantly. Type in any field and the others update live.
Binary Bit Display
Custom Base Converter
Convert to or from any base between 2 and 36. Type a value here to update all fields above, or type above to see the result here.
Understanding Number Bases
A number base (or radix) determines how many unique digits are used to represent numbers. We use base 10 (decimal) in everyday life because we have 10 fingers, but computers work in base 2 (binary) since transistors have two states: on and off.
Common Number Bases
| Base | Name | Digits | Used For |
|---|---|---|---|
| 2 | Binary | 0-1 | Digital circuits, low-level programming |
| 8 | Octal | 0-7 | Unix file permissions, legacy systems |
| 10 | Decimal | 0-9 | Everyday counting, mathematics |
| 16 | Hexadecimal | 0-9, A-F | Memory addresses, colors, byte values |
Quick Reference
| Decimal | Binary | Octal | Hex |
|---|---|---|---|
| 0 | 0000 | 0 | 0 |
| 8 | 1000 | 10 | 8 |
| 10 | 1010 | 12 | A |
| 15 | 1111 | 17 | F |
| 16 | 10000 | 20 | 10 |
| 255 | 11111111 | 377 | FF |
Common Use Cases
CSS Colors: Hex values like #FF5733 represent RGB color channels (255, 87, 51 in decimal).
IPv4 Addresses: Each octet is a decimal number 0-255 (one byte, or 8 binary digits).
File Permissions: Unix chmod uses octal, e.g., 755 means rwxr-xr-x.
Memory Addresses: Displayed in hexadecimal for compact representation of large binary values.
This tool supports arbitrarily large numbers using BigInt. Your data never leaves your browser.