Math Tools
Online Base Converter and Calculator
Convert integers exactly between bases 2–36, including binary, octal, decimal, and hexadecimal, with clear digit validation.
Exact integer conversion
Enter a number and its base
Use 0–9 and A–Z. Bases 2–36 and integers up to 4,096 digits are supported.
Equivalent values
Conversion results
Quick answer
How do I convert binary, octal, decimal, and hexadecimal numbers?
Choose the source base and enter an integer. The tool immediately expresses the same value in bases 2, 8, 10, 16, and a custom target base, using 0–9 and A–Z for digit values from 0 to 35.
How to use this tool
- Choose a source base from 2 through 36 and enter an integer using digits valid for that base.
- Select Convert, or wait for the live update, to see bases 2, 8, 10, 16, and your custom target base.
- Copy an individual result or export the current report to print, Excel, PDF, or TXT.
How the calculation works
The parser reads digits from left to right, multiplying the accumulated value by the source base before adding the next digit. It then formats that exact integer in each target base with BigInt, avoiding Number precision loss for large integers. Signed integers and bases from 2 through 36 are supported.
Examples
| Example | Input | Expected result |
|---|---|---|
| Binary to decimal | |
11 in base 10, 13 in base 8, and B in base 16 |
| Hexadecimal to decimal | |
47 in base 10, 101111 in base 2, and 57 in base 8 |
| Decimal to hexadecimal | |
7D in base 16 and 1111101 in base 2 |
Limitations
- The tool accepts integers only, not decimal points, fractions, scientific notation, or prefixes such as 0x and 0b.
- Input is limited to 4,096 digits to bound browser processing and memory use.
- Every digit must be smaller than the source base; for example, digit 2 is invalid in base 2.
- Exports use the most recently calculated result. Recalculate after changing an input before exporting.
Frequently asked questions
Which number bases are supported?
Bases 2 through 36 are supported. Bases above 10 use A through Z for digit values 10 through 35, and input is case-insensitive.
Can the converter handle large integers?
Yes. It uses BigInt and a digit-by-digit parser to keep integer values exact, with a 4,096-digit input limit to keep the page responsive.
Are negative numbers supported?
Yes. Put one minus or plus sign before the digits. For example, -FF in base 16 equals -255 in base 10.
Is my number stored?
No. Conversion and file generation happen in your browser, and the entered value is not sent to the server.
References
- ECMAScript Language Specification — BigInt Type Verified 2026-07-31
- ECMAScript Language Specification — BigInt.prototype.toString Verified 2026-07-31
Content and calculation method last reviewed: