Enter a decimal number to convert it to binary instantly. Handy for Class 11–12 computer science — see the side-by-side reference table below, or open the full converter for all four bases at once.
base 10 → base 2 · Open the full converter →
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A number written in decimal (base 10) is rewritten in binary (base 2). For example, 42 in decimal equals 101010 in binary. The full converter at /tools/ shows binary, octal, decimal and hexadecimal together.
| Decimal | Binary |
|---|---|
| 1 | 1 |
| 2 | 10 |
| 4 | 100 |
| 8 | 1000 |
| 10 | 1010 |
| 16 | 10000 |
| 42 | 101010 |
| 255 | 11111111 |
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