Number base converter
Convert integers between binary, decimal, hexadecimal and bases from 2 to 36.
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How we handle your data →How to use this tool
- Enter an integer without 0x, 0b or separators.
- Choose input and output bases from 2 to 36.
- Check the sign and remember that leading zeros are normalized.
An example you can verify
Convert a hexadecimal value to decimal without losing precision.
Example input
FF
Expected result
255
F represents 15: 15 × 16 + 15 = 255. In base 2 the same number is 11111111.
Number base converter: uses and practical guidance
Converting number bases represents the same integer with a different digit system. It helps with binary exercises, hexadecimal values and numeric identifier inspection. The tool supports bases from two to thirty six. Changing representation does not change quantity: the visible digits depend on the selected base, just as decimal ten has a different spelling in binary. Identify the number’s interpretation before treating an arbitrary character string as a numeric input.
Select the source base and check that every digit is valid in it. Binary uses only zero and one, while higher bases use letters for additional values. Follow the input field’s rules rather than assuming a prefix from another programming language will automatically be accepted. A hexadecimal looking string could also be ordinary text or an identifier, so its intended meaning should come from the surrounding system or exercise, not appearance alone.
The calculation works with integers and can handle values beyond ordinary JavaScript number precision using large integer logic. It does not convert fractions or decimal separated quantities. A negative sign represents a negative mathematical amount; that is different from a fixed width two’s complement binary representation. Define width and signed bit conventions separately when interpreting a hardware register or encoded field. Base conversion alone does not supply those missing constraints.
Check by converting the result back to the original base and trying a small familiar value to confirm the selections were not reversed. Leading zeros may disappear because they do not change the integer value; keep the original string when they express a required width or code format. Text Base64 is a different operation, not merely writing an integer in base sixty four. Use that converter when bytes of text need transport encoding.
A practical check before using the result
A round trip trial can use a positive integer, zero and a negative integer. Convert each and return to the source base to confirm its value. For fixed width codes, also retain original formatting and leading zeros, since numeric equivalence does not necessarily preserve presentation or the receiver’s required width.
Settings and limits
Enter an integer and choose its input and output bases. Digits are 0–9 and letters A–Z, without 0x or 0b prefixes, internal spaces or fractional parts. Supports + or − signs and up to 2,048 digits. Arbitrary-precision integer arithmetic retains exact values for large numbers.
Frequently asked questions
Are leading zeros retained?
No. It converts the numeric value and returns a normalized representation. Output letters are uppercase and negative zero becomes 0.
Are my data stored on a server?
No. Content and files are processed in your browser without an account. Closing the page loses unsaved results.