About this number base converter
A number base, or radix, is how many different digits a number system uses. We count in base 10, computers work in base 2, and programmers often write values in base 16 (hexadecimal) or base 8 (octal) because they map neatly onto bits. This converter handles any base from 2 to 36, where digits above 9 are written with the letters A to Z. It uses exact whole-number arithmetic, so even very long numbers convert without rounding. The step-by-step tables show both halves of the method: adding up place values to reach decimal, then dividing repeatedly to build the new base.
How to convert between number bases
- Enter the number. Type a whole number. Prefixes such as 0x, 0b, and 0o are accepted when they match the base, and a minus sign is allowed.
- Choose the bases. Pick the From base the number is written in and the To base you want, or press an example such as DEC → HEX.
- Press Convert. The result appears with the number in binary, octal, decimal, and hex.
- Follow the steps. Read the place value table and the division table to see how the result was worked out.
Frequently asked questions
How do I convert a number to decimal by hand?
Multiply each digit by the base raised to the power of its position, counting from 0 on the right, and add the results. For binary 1101 that is 8 + 4 + 0 + 1 = 13.
How do I convert decimal to another base?
Divide by the new base, write down the remainder, and repeat with the quotient until it reaches 0. The remainders read from last to first are the digits of the answer.
Why does base 36 stop at Z?
Base 36 uses the ten digits 0 to 9 plus the 26 letters A to Z, which is every standard alphanumeric character. Letters are not case sensitive, so ff and FF are the same.
Are fractions or decimal points supported?
No, only whole numbers, including negative ones. Fractions often have no exact form in another base, for example 0.1 in decimal repeats forever in binary.
Is there a size limit?
You can enter up to 256 digits. The conversion uses exact big-integer arithmetic, so long numbers such as 128-bit values keep every digit.