Number Base Converter
Convert whole numbers between binary, octal, decimal, and hexadecimal. Enter a value in any field and the rest update instantly — perfect for programming, homework, and debugging.
Understanding number bases
We usually count in decimal (base 10), but computers work in binary (base 2) — just 0s and 1s. Hexadecimal (base 16, digits 0–9 and A–F) is a compact way to write binary, since each hex digit maps to exactly four bits. Octal (base 8) shows up in file permissions and older systems. This tool converts a whole number between all four at once.
Quick examples
- Decimal 10 = binary 1010 = octal 12 = hex A
- Decimal 255 = binary 11111111 = hex FF
- Decimal 16 = binary 10000 = hex 10
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Frequently asked questions
What is 255 in hexadecimal?
255 in decimal is FF in hexadecimal, and 11111111 in binary. It's the largest value in a single byte.
How do I convert binary to decimal?
Add up the place values of each 1 bit (…8, 4, 2, 1). For example 1010 = 8 + 2 = 10. Or just type it above and read the decimal field.
Does it handle decimals or negatives?
This converter works with non-negative whole numbers, which covers the vast majority of base-conversion needs.