Number base converter
Convert signed whole numbers between binary, octal, decimal, and hexadecimal.
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How to use it
Enter a whole number and choose its source and destination base.
Good to know
Uses BigInt, so large integers are not rounded.
Change a whole number’s notation
Choose the source and destination bases, then enter the number without a prefix. For example, FF from hexadecimal to decimal becomes 255. Negative values are allowed, so decimal -10 becomes binary -1010.
Use the correct digits for the selected base
Binary accepts 0 and 1; octal accepts 0–7; decimal accepts 0–9; hexadecimal additionally accepts A–F. The converter uses exact integer arithmetic, so it does not round large whole numbers.
Fractions, prefixes such as 0x, scientific notation, and decimal points are not accepted. Enter at most 1,000 digits. For text encoded as binary bytes, use the binary translator instead.