Number Base Converter
Convert between binary, octal, decimal, and hex simultaneously. Type in any field — all others update instantly.
⬛ Binary
Base 2
🔶 Octal
Base 8
🟢 Decimal
Base 10
💜 Hexadecimal
Base 16
Paste multiple values (one per line). Select the input base and click Convert.
Input values
Results
Results appear here after conversion.
Enter a number and see the step-by-step conversion process for each base.
Frequently Asked Questions
Group binary digits into sets of 4 from the right (pad with leading zeros if needed). Each group of 4 bits maps to one hex digit: 0000=0 … 1111=F. For example, binary 10110100 → groups 1011 0100 → hex B4. Our converter handles this instantly — just type in the Binary field.
These are number systems with different bases (sets of digits). Binary (base 2) uses 0–1 and is used internally by computers. Octal (base 8) uses 0–7, historically used in early computing. Decimal (base 10) uses 0–9 and is the everyday human system. Hexadecimal (base 16) uses 0–9 and A–F, widely used in programming to represent binary data compactly. One hex digit = 4 binary bits; two hex digits = one byte.
Divide the decimal number by 2 repeatedly and record each remainder. Read the remainders from bottom to top. For 45: 45÷2=22 R1, 22÷2=11 R0, 11÷2=5 R1, 5÷2=2 R1, 2÷2=1 R0, 1÷2=0 R1 → binary 101101. Use the Steps tab to see this breakdown for any number.
The prefix
0x is standard programming notation for hexadecimal. 0xFF = decimal 255. Similarly, 0b means binary (0b1010 = 10) and 0o means octal (0o17 = 15). Our converter auto-detects all three prefixes — paste any prefixed number and it parses the correct base automatically.
Yes. The converter uses JavaScript BigInt, which supports arbitrarily large integers with no precision loss. Standard JavaScript numbers lose precision above 2^53−1 (~9 quadrillion). BigInt has no such limit, so you can convert 64-bit, 128-bit, or larger numbers exactly.