13 in binary = 1101
In other bases: hexadecimal D, octal 15. The binary number has 4 bits.
Divide by 2 repeatedly and note each remainder. Read the remainders from bottom to top.
| Division | Quotient | Remainder |
|---|---|---|
| 13 ÷ 2 | 6 | 1 |
| 6 ÷ 2 | 3 | 0 |
| 3 ÷ 2 | 1 | 1 |
| 1 ÷ 2 | 0 | 1 |
Remainders bottom to top: 1101.
| Power of 2 | 8 | 4 | 2 | 1 |
|---|---|---|---|---|
| Bit | 1 | 1 | 0 | 1 |
Add the powers of 2 where the bit is 1: 8 + 4 + 1 = 13.
Need another number or the reverse direction? Use the binary to decimal converter or the text to binary converter.
| Decimal | Binary | Hex | Octal |
|---|---|---|---|
| 9 | 1001 | 9 | 11 |
| 10 | 1010 | A | 12 |
| 11 | 1011 | B | 13 |
| 12 | 1100 | C | 14 |
| 14 | 1110 | E | 16 |
| 15 | 1111 | F | 17 |
| 16 | 10000 | 10 | 20 |
| 17 | 10001 | 11 | 21 |