Decimal to binary converter
Convert a whole number to binary, or switch direction to turn binary back into a number.
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How to convert decimal to binary
Divide the number by 2 and write down the remainder. Keep dividing the result by 2 until you reach 0. Read the remainders from bottom to top.
For 13: 13 ÷ 2 = 6 r1, 6 ÷ 2 = 3 r0, 3 ÷ 2 = 1 r1, 1 ÷ 2 = 0 r1. Reading up gives 1101.
Place values
| Bit | Value |
|---|---|
| 27 | 128 |
| 26 | 64 |
| 25 | 32 |
| 24 | 16 |
| 23 | 8 |
| 22 | 4 |
| 21 | 2 |
| 20 | 1 |
Years in binary
2025 is 11111101001 and 2000 is 11111010000. To turn a full birthday into binary, use the binary birthday converter.
Questions
What is 10 in binary?
10 in binary is 1010.
What is 100 in binary?
100 in binary is 1100100.
How big a number can I convert?
Any whole number. Large numbers are handled exactly, not rounded.