Number Base Converter

About Number base converter

Converts an integer between any bases from 2 to 36. Enter a value, choose the base it is written in, and see it in binary, octal, decimal, hexadecimal, base 32 and base 36, or in every base at once. Arithmetic uses BigInt, so huge values stay exact.

How to use it

1. Type the number into the Value box. Spaces and underscores are ignored as digit separators.
2. Set the Source base with the menu or the Quick source base buttons (2, 8, 10, 16, 32, 36).
3. Read the Converted value table, and switch on Show every base from 2 to 36 for the full list.
4. Toggle Group digits to space the digits in fours for binary and hex, and threes elsewhere, and press Copy on any row.

255 in six bases

255 in base 10

Base 2 11111111, base 8 377, base 16 ff, base 32 7v, base 36 73

When to use it

• Checking a programming exercise that asks for a value in base 7 or base 12.
• Shortening a large ID by re-writing it in base 36.
• Converting a 64-bit or larger number without losing precision.
• Reading a hexadecimal address as decimal while debugging.

Questions about Number base converter

Which digits does each base use?

Bases up to 10 use 0 to the base minus one. Larger bases add lowercase letters, so base 16 goes up to f and base 36 up to z. Entering a digit that is too big for the base explains what is allowed.

How large can the number be?

Any length. 2 to the power 64, or 18446744073709551616, comes out as 10000000000000000 in hex without any rounding.

Are negative numbers supported?

Yes, a leading minus sign is kept in every result. The tool writes signed magnitudes rather than two's complement patterns.

Can I type 0xff?

Not in base 16, where the x is flagged as an invalid digit. In base 36, oddly, x is a valid digit, so 0xff would be read as an ordinary base 36 number. Drop prefixes and choose the base explicitly.

Does Copy include the grouping spaces?

No. Copy always gives the plain digits without separators, even when Group digits is switched on.

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