Number Base Converter

Enter a value and its base to instantly see the equivalent in binary, octal, decimal and hexadecimal.

Binary
101010
Octal
52
Decimal
42
Hexadecimal
2A

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How to use

  1. Enter a value.
  2. Choose the base that value is in.
  3. Read the equivalent in all four bases below.

What is this tool?

Number Base Converter takes a number in binary, octal, decimal or hexadecimal and instantly shows its equivalent in all four bases at once. It validates that your input only contains characters valid for the selected base, so you can catch mistakes immediately.

Common uses

  • Converting a hexadecimal color or memory address to decimal
  • Checking a binary value while learning computer science fundamentals
  • Converting between number bases for a programming assignment
  • Debugging a value that's displayed in an unfamiliar base

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FAQ

Which bases are supported?

Binary (base 2), octal (base 8), decimal (base 10) and hexadecimal (base 16).

What characters are valid for each base?

Binary uses 0-1, octal uses 0-7, decimal uses 0-9, and hexadecimal uses 0-9 and A-F.

How large a number can I convert?

The converter works reliably for any number within JavaScript's safe integer range, which covers the vast majority of everyday use cases.