Base Converter
The base converter tool allows you to convert numbers between different bases. You can convert numbers from base 2 to base 36 — including the four most common: binary (2), octal (8), decimal (10), and hexadecimal (16).
What Is a Number Base?
A number base (or "radix") is the number of unique digits a numbering system uses before it carries over to a new place value. The base you use every day — base 10 (decimal) — has ten digits (0–9). When you count past 9, you carry over to a new column: 9 becomes 10. Every other base works the same way, just with a different digit count.
For bases above 10, letters stand in for extra digits: base 16 (hexadecimal) uses a–f for the values 10–15, and this tool extends that pattern all the way up to base 36, using a–z for values 10–35.
Common Base Reference
| Base | Name | Digits used | Example |
|---|---|---|---|
| 2 | Binary | 0–1 | 100 (binary) = 4 (decimal) |
| 8 | Octal | 0–7 | 100 (octal) = 64 (decimal) |
| 10 | Decimal | 0–9 | 100 (decimal) = 100 |
| 16 | Hexadecimal | 0–9, a–f | 100 (hex) = 256 (decimal) |
| 36 | Base 36 | 0–9, a–z | Highest base this tool supports |
How to Use This Base Converter
- Enter your number in the Number field.
- Choose the base that number is currently written in under From base.
- Choose the base you want to convert it to under To base.
- The converted result appears instantly in the Results field — no button click needed.
Frequently Asked Questions
Why do computers use binary (base 2)? Computer hardware is built from switches that are only ever fully on or off — two states, which maps directly onto binary's two digits (0 and 1). Every other numeric representation a computer displays (decimal, hex) is really binary underneath, translated for humans to read.
Why is hexadecimal (base 16) so common in programming?
Because 16 is a power of 2, each hex digit maps cleanly onto exactly 4 binary digits (bits), making hex a compact, human-readable shorthand for binary data. That's why you'll see hex used for color codes (#ff0000), memory addresses, and byte values.
What happens if I enter a digit that's invalid for the selected base?
The tool shows "Invalid character" — for example, entering 9 while "From base" is set to 8 (octal) is invalid, since octal only uses digits 0–7.
Can I convert a negative number? No — this tool works with non-negative whole numbers only. Negative numbers and decimals with fractional parts aren't supported.
Is there a limit to how large a number I can convert? The tool relies on standard JavaScript number handling, so extremely large numbers (beyond about 2^53) may lose precision. For everyday conversions — IDs, color codes, small binary/hex values — this isn't a concern.
