Convert numbers between any bases
A base is how many distinct digits a number system uses before it rolls over to the next place. This calculator converts a value from any base between 2 and 36 into any other, and always shows the four everyday systems — decimal, binary, octal, and hexadecimal — side by side.
How positional bases work
In base 10 the digits are 0 to 9 and each place is worth ten times the one to its right. Base 2 uses only 0 and 1 with places worth powers of two; base 16 adds the letters A to F for the values ten through fifteen. The conversion reads your number into a plain count, then rewrites that count in the target base.
Why binary and hex matter
Computers store everything in binary, but long binary strings are hard to read, so programmers group them into hexadecimal — each hex digit stands for exactly four binary digits. That is why color codes, memory addresses, and byte values are written in hex.
Related tools
For remainders and clock arithmetic, use the modulo calculator; to factor a number, the prime factorization calculator.
Worked example
The decimal number 255 is 11111111 in binary, 377 in octal, and FF in hexadecimal — the largest value a single byte can hold.
FAQ
What is the highest base supported?
Base 36, which uses all ten digits plus the 26 letters A to Z. Beyond that there are no standard symbols for the extra digit values.
Can it handle letters in the input?
Yes — for bases above 10, enter letters for the higher digits (A for 10, B for 11, and so on). Case does not matter.