Number Base Converter
Select your input base, enter a number — instantly see conversions to all other bases.
Number exceeds JavaScript's safe integer range — results may be imprecise.
Number Bases
Decimal — Base 10
Everyday number system using digits
0–9. Each position is a power of 10. Example: 255 = 2×10² + 5×10¹ + 5×10⁰. Binary — Base 2
Used internally by all computers. Only digits
0 and 1. Each position is a power of 2. Example: 11111111 = 255. Octal — Base 8
Uses digits
0–7. Common in Unix permissions (chmod 755). Each octal digit = exactly 3 binary bits. Hexadecimal — Base 16
Uses
0–9 then A–F. Used in CSS colors & memory addresses. Each hex digit = exactly 4 binary bits. Quick Reference — click a row to load it
| Dec | Binary | Oct | Hex |
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