🔢 Base Converter

One number, every radix at once. Type in any base and read it in all the others — the conversion uses your browser's BigInt, so it stays exact far beyond the 2⁵³ limit of ordinary JavaScript numbers (a 64-bit hex value like FEDCBA9876543210 converts digit-perfect).

How radix conversion works

Reading a number in base b is Horner's rule: start at zero, and for each digit multiply by b and add the digit's value. Writing it in base b is the mirror image: divide repeatedly by b and collect the remainders from the last one backward. That is exactly what this page computes, in BigInt, so no intermediate value ever rounds. Digits above 9 use A–Z, which is why the practical ceiling for a single-symbol base is 36.

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