Integer Base Converter
Convert an integer between any number bases from 2 to 36 — binary, octal, decimal, hexadecimal or any custom base. Handles negative numbers and arbitrarily large integers, and shows the value in all four common bases at once.
Input
Digits 0-9 and A-Z, case-insensitive. A leading - is allowed.
The base the number above is written in (2-36).
The base to convert to (2-36).
Output
In common bases
| Base | Value |
|---|---|
| No data yet | |
Guides
The Integer Base Converter turns a whole number written in one number base into any other base from 2 to 36. Enter a value, pick the base it is currently written in, choose the base you want, and the converted result appears instantly — alongside a handy table showing the same number in binary, octal, decimal and hexadecimal.
What is a number base?
A number base (also called a radix) is the number of distinct digits a positional numbering system uses. Decimal — the everyday system — is base 10 and uses the digits 0 through 9. Binary is base 2 and uses only 0 and 1. Hexadecimal is base 16 and extends the digits with the letters A–F to represent the values 10 through 15. Bases above 10 keep borrowing letters, so base 36 uses every digit 0–9 and every letter A–Z, giving 36 symbols in total. The value of a number never changes when you convert it between bases; only the way it is written down does. The decimal number 255, binary 11111111, and hexadecimal FF are three spellings of the same quantity.
How to use this tool
- Type the number into the Number field. Digits above 9 are written as letters, so hexadecimal 255 is
FF. Input is case-insensitive, and you can prefix a-for negative numbers. - Set From base to the base your number is already written in.
- Set To base to the base you want the result in.
- Read the converted value, and use the In common bases table to see the binary, octal, decimal and hexadecimal forms at a glance.
Only digits that are valid for the chosen "from" base are accepted — for example, the digit 9 is rejected in base 2, and G is rejected in base 16 — so you get a clear message instead of a wrong answer.
FAQ
Which bases are supported? Any base from 2 to 36, in either direction. That covers binary (2), octal (8), decimal (10) and hexadecimal (16), plus every base in between and beyond up to base 36.
Can it handle very large numbers? Yes. The converter uses arbitrary-precision integer arithmetic, so numbers far larger than a spreadsheet or ordinary calculator can hold are converted exactly, with no rounding or loss of the least significant digits.
Does it work with negative numbers? Yes. Put a minus sign in front of the number and the sign is preserved through the conversion.
Why are the results shown in uppercase?
Digits above 9 are letters, and uppercase (for example FF rather than ff) is the most common convention for hexadecimal and other high bases. The value is identical either way.
Is my data sent anywhere? No. The conversion runs entirely in your browser, so nothing you type leaves your device.
Common uses
Programmers convert between hexadecimal, binary and decimal when reading memory addresses, color codes, bitmasks and file formats. Students and teachers use base conversion to learn how positional notation works. Base 36 is sometimes used to pack numeric IDs into short alphanumeric strings. Whatever the reason, this tool gives an exact answer for any base from 2 to 36.