Number Base Converter Calculator
Convert any whole number from one positional base to another, between base 2 and base 36, using digits 0-9 and A-Z.
From base
To base
How does this calculator work?
To change a number between bases, read each digit in the source base to get its decimal value (multiply-and-add), then repeatedly divide that value by the target base, collecting remainders as the new digits. This converter does both steps for any base from 2 to 36, including binary, octal, and hexadecimal.
Formula
How this is calculated
Enter the number as a digit string, then choose its current (source) base and the target base, each between 2 and 36. Digits use the usual 0-9 then A-Z ordering, where A=10, B=11, up to Z=35. Every digit must be smaller than the source base; otherwise the input is invalid.
The converter first reads the digit string in the source base to obtain its value in plain decimal: starting from the most significant digit it repeatedly multiplies the running total by the base and adds the next digit value (Horner's method, equivalent to value = Σ digitᵢ · b1ⁱ). It then re-expresses that value in the target base by repeated division: the remainder of dividing by the target base gives the next least-significant digit, and the quotient is carried forward until it reaches zero.
The tool handles an optional leading minus sign and ignores surrounding whitespace. It works on integers; fractional parts are not supported. Because the intermediate value is a standard floating-point number, results are exact for magnitudes up to about 2^53.
Frequently asked questions
Any integer base from 2 to 36. Base 36 uses all ten digits plus the 26 letters A-Z.
Each digit must be valid for the source base. For example, the digit 2 is not allowed in base 2, and the letter G is not allowed below base 17.
No, it converts whole numbers only. Remove any fractional part before converting.
Also known as
TG we-Calculate Editorial Team. (2026). Number Base Converter Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/number-base-converter-calculator
TG we-Calculate Editorial Team. "Number Base Converter Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/number-base-converter-calculator.
TG we-Calculate Editorial Team, "Number Base Converter Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/number-base-converter-calculator
@misc{wecalculate_number_base_converter_calculator, title = {Number Base Converter Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/number-base-converter-calculator}}, year = {2026}, note = {TG we-Calculate} }
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