What bases are supported?

Any base from 2 (binary) to 36 is supported. Bases above 10 use letters: base 16 uses 0-9 then A-F, and base 36 uses 0-9 then A-Z.

How does the calculator avoid rounding errors?

It parses each operand into an exact integer, performs the arithmetic in plain decimal, and converts the exact result back to the chosen base, so there is no floating-point drift for whole-number inputs.

What happens when subtraction goes negative?

Negative results are fully supported and shown with a leading minus sign in both the chosen base and decimal, for example subtracting a larger number from a smaller one in base 2.

Why is a digit rejected?

A digit is rejected when it is not valid for the selected base. In base 8 the digits 8 and 9 are invalid, and in base 2 only 0 and 1 are allowed. The tool names the offending digit.

Can it handle very large numbers?

Operands and results are accurate up to the JavaScript safe integer limit of 9007199254740991. Beyond that point precision can no longer be guaranteed, so the tool keeps inputs within that range.

Base-N Arithmetic Calculator

Doing math directly in any radix

Most calculators only work in decimal. This tool lets you add, subtract, and multiply numbers written in any base from 2 to 36, which is handy for binary, octal, and hexadecimal work as well as exotic bases used in encoding schemes. Digits beyond 9 use the letters A–Z, so base 16 runs 0–9 then A–F and base 36 runs 0–9 then A–Z.

How it works

Each operand is first parsed from its base into an exact integer value, using the positional rule where the digit at position i from the right contributes digit × base^i. The arithmetic is then performed on those integers:

value = parseInt(operand, base)
result = a + b   (or a - b, or a * b)

Finally the exact integer result is converted back into the chosen base with repeated division and remainder, and the same result is shown in decimal for cross-checking. Negative results keep a leading minus sign in both displays.

Example and tips

In base 16, FF + 1 equals 100 (which is 256 in decimal). In base 2, 1011 × 11 equals 100001 (11 × 3 = 33). If you enter a digit that does not belong to the base — such as a 2 in binary — the calculator highlights the bad digit instead of silently producing a wrong answer. Keep operands within the safe integer range so the exact-integer guarantee holds.