Number Base Converter
Convert numbers between binary, octal, decimal and hexadecimal. Enter a value in any base and see it in all four.
Result
Decimal
—
Enter a whole number in your chosen base.
Enter a whole number in the base you have, choose that base, and see it converted to binary, octal, decimal and hexadecimal at once.
Frequently asked questions
How do I convert binary to decimal?
Each binary digit represents a power of two. Reading 1010 from the right: 0×1 + 1×2 + 0×4 + 1×8 = 10. This converter does it instantly in both directions.
What is hexadecimal used for?
Hexadecimal (base 16) is a compact way to write binary data — each hex digit maps to exactly four binary digits. It's widely used for colour codes, memory addresses and byte values.