Binary to Decimal Converter
Convert between binary, decimal, hexadecimal and octal in real time — type in any field.
Quick Reference
| Decimal | Binary | Hex | Octal |
|---|---|---|---|
| 0 | 0000 | 0 | 0 |
| 1 | 0001 | 1 | 1 |
| 8 | 1000 | 8 | 10 |
| 10 | 1010 | A | 12 |
| 15 | 1111 | F | 17 |
| 16 | 10000 | 10 | 20 |
| 255 | 11111111 | FF | 377 |
How Number Base Conversion Works
Binary (base 2) uses only 0s and 1s — each digit represents a power of 2. To convert 1010 to decimal: (1×8)+(0×4)+(1×2)+(0×1) = 10. Hexadecimal (base 16) uses digits 0–9 and A–F, where A=10 and F=15. One hex digit represents exactly 4 binary bits, making it a compact notation used throughout computing for colour codes (#2563EB), memory addresses and machine code. Octal (base 8) uses digits 0–7; each octal digit maps to 3 binary bits. Type any value above to see all four representations update instantly.
Frequently Asked Questions
How do I convert binary to decimal?
Sum the positional values (powers of 2) for every position containing a 1, reading from right to left. Binary 1010 = 8+2 = 10 decimal.
How do I convert decimal to hexadecimal?
Repeatedly divide by 16, writing remainders from bottom to top. Remainders 10–15 become A–F. Or type your decimal value above for instant conversion.
What is hexadecimal used for in computing?
Hex represents binary values compactly — one hex digit = 4 binary bits. It's used in web colour codes, memory addresses, machine code and low-level debugging.
How do you convert binary to octal?
Group binary digits into sets of 3 from the right (pad with leading zeros if needed). Each group maps directly to one octal digit. Binary 101010 → groups 101 010 → octal 52.