25 in binary = 11001 (1 1001)
In other bases: hexadecimal 19, octal 31. The binary number has 5 bits.
Divide by 2 repeatedly and note each remainder. Read the remainders from bottom to top.
| Division | Quotient | Remainder |
|---|---|---|
| 25 ÷ 2 | 12 | 1 |
| 12 ÷ 2 | 6 | 0 |
| 6 ÷ 2 | 3 | 0 |
| 3 ÷ 2 | 1 | 1 |
| 1 ÷ 2 | 0 | 1 |
Remainders bottom to top: 11001.
| Power of 2 | 16 | 8 | 4 | 2 | 1 |
|---|---|---|---|---|---|
| Bit | 1 | 1 | 0 | 0 | 1 |
Add the powers of 2 where the bit is 1: 16 + 8 + 1 = 25.
Need another number or the reverse direction? Use the binary to decimal converter or the text to binary converter.
| Decimal | Binary | Hex | Octal |
|---|---|---|---|
| 21 | 10101 | 15 | 25 |
| 22 | 10110 | 16 | 26 |
| 23 | 10111 | 17 | 27 |
| 24 | 11000 | 18 | 30 |
| 26 | 11010 | 1A | 32 |
| 27 | 11011 | 1B | 33 |
| 28 | 11100 | 1C | 34 |
| 29 | 11101 | 1D | 35 |