Number Base Converter
Convert between binary (base 2), octal (base 8), decimal (base 10) and hexadecimal (base 16). Supports numbers of any size thanks to BigInt, with optional digit grouping for readability.
Conversions
How to use: Number bases
- 1Pick the input base: binary, octal, decimal or hexadecimal.
- 2Type the number.
- 3Read and copy its value in the other bases.
What is it for?
- Convert colors or memory addresses from hex to decimal.
- Solve computer science and electronics exercises.
- Work with permissions, bit masks and registers.
Binary, octal, decimal and hexadecimal
Numeral systems
Decimal uses ten digits; binary, two; octal, eight; and hexadecimal, sixteen (0–9 and A–F). Each hexadecimal digit equals exactly four bits.
Where they are used
Binary in electronics and network masks, hexadecimal in colors (#FF0000), memory addresses and dumps, octal in Unix permissions (chmod 755).
Manual conversion
To go from decimal to binary, divide repeatedly by 2 and read the remainders bottom to top. To go from binary to hexadecimal, group bits in fours.
Related tools
Frequently asked questions
How do I go from decimal to binary?+
Divide the number by 2 repeatedly and note the remainders from bottom to top. This tool does it instantly for any base.
What is hexadecimal?+
It's base 16: it uses digits 0-9 and letters A-F. Every 4 bits equal one hexadecimal digit, which is why it's common in programming.
What size does it support?+
There's no practical limit: it uses BigInt, so you can convert numbers with hundreds of digits.