Free Online ToolUpdated September 2026
Decimal to Binary Converter — Base 10 to Base 2 Calculator
Convert decimal numbers to binary code with step-by-step repeated division by 2. Free calculator, bit expansion, and reference tables.
Multi-Base Conversion Dashboard
Type in any input to instantly convert across bases, signed binary, floats, and ASCII text.
Instant Test Pills::
Decimal To Binary Reference & Conversion Matrix
Instant numerical reference comparing Hex, Decimal, Binary, and Octal values.
| Hex (Base 16) | Decimal (Base 10) | Binary (Base 2) | Octal (Base 8) |
|---|---|---|---|
| 0x0 | 0 | 0000 | 0 |
| 0x1 | 1 | 0001 | 1 |
| 0x2 | 2 | 0010 | 2 |
| 0x3 | 3 | 0011 | 3 |
| 0x4 | 4 | 0100 | 4 |
| 0x5 | 5 | 0101 | 5 |
| 0x6 | 6 | 0110 | 6 |
| 0x7 | 7 | 0111 | 7 |
| 0x8 | 8 | 1000 | 10 |
| 0x9 | 9 | 1001 | 11 |
| 0xA | 10 | 1010 | 12 |
| 0xB | 11 | 1011 | 13 |
| 0xC | 12 | 1100 | 14 |
| 0xD | 13 | 1101 | 15 |
| 0xE | 14 | 1110 | 16 |
| 0xF | 15 | 1111 | 17 |
How to Perform This Conversion in Code
Python
# Convert value across number bases
num = 42
print(bin(num)) # Binary: 0b101010
print(hex(num)) # Hex: 0x2a
print(oct(num)) # Octal: 0o52JavaScript / TypeScript
// Convert value across number bases
const num = 42;
console.log(num.toString(2)); // Binary: "101010"
console.log(num.toString(16)); // Hex: "2a"
console.log(num.toString(8)); // Octal: "52"