Number Base Converter
Convert between binary, octal, decimal, hex, and any base 2–36 — live as you type.
Input
Binary · Base 2
0b11111111
Octal · Base 8
0o377
Decimal · Base 10 (input)
255
Hexadecimal · Base 16
0xFF
Custom Base (2–36)
7VAbout this tool
A real-time number base converter for developers, students, and engineers. Convert any integer between binary (base 2), octal (base 8), decimal (base 10), hexadecimal (base 16), and any custom base up to 36. All conversions happen instantly in your browser.
How to use it
Quick steps to get the most out of this utility.
- 1
Select input base
Choose binary, octal, decimal, or hex as your source format.
- 2
Type your number
The tool converts it to all other bases instantly.
- 3
Read all results
Binary, octal, decimal, and hex are shown side by side.
- 4
Use custom base
Expand the Custom Base section for base-32, base-36, or any other.
When to use each base
- Binary (base 2): bitwise operations, hardware registers, network masks
- Octal (base 8): Unix file permissions (chmod 755)
- Decimal (base 10): human-facing numbers, most math
- Hexadecimal (base 16): memory addresses, color codes, byte-level protocols, crypto hashes
Frequently asked questions
What is base conversion?+
Base conversion is the process of representing the same number in different numeral systems. Decimal (base 10) uses digits 0–9, binary (base 2) uses 0–1, octal (base 8) uses 0–7, and hexadecimal (base 16) uses 0–9 plus A–F.
Why do developers use hexadecimal?+
Hex is compact: one hex digit represents exactly 4 binary bits (a nibble), so two hex digits represent a full byte. This makes hex ideal for memory addresses, color codes (#FF5733), and byte-level debugging.
Why does binary matter in programming?+
Computers operate on binary at the hardware level. Understanding binary is essential for bitwise operations (AND, OR, XOR, shifts), low-level protocols, and working with flags and masks.
What is the octal number system used for?+
Octal (base 8) is primarily used in Unix/Linux file permission notation (chmod 755) because each digit maps to exactly 3 binary bits, representing read/write/execute for owner, group, and others.
Can this tool convert negative numbers?+
This tool converts non-negative integers. Negative number representation (two's complement) depends on the bit width of the target system and is not covered here.
Keep exploring
More utilities and reading from Toolisk.