Decimal to Binary
Convert decimal to binary instantly — repeatedly divide the number by two and read the remainders from bottom to top. Type in either box to convert both ways. Handy for programming, bitmasks and understanding how an everyday number looks to a computer in ones and zeros.
Decimal to Binary conversion table
| Decimal | Binary |
|---|---|
| 1 | 1 |
| 2 | 10 |
| 4 | 100 |
| 8 | 1000 |
| 10 | 1010 |
| 16 | 10000 |
| 32 | 100000 |
| 64 | 1000000 |
| 100 | 1100100 |
| 128 | 10000000 |
| 255 | 11111111 |
| 256 | 100000000 |
How to convert decimal to binary
To convert decimal to binary, repeatedly divide the number by two and read the remainders from bottom to top. For example, 10 in decimal is 1010 in binary. The converter above validates each digit for its base and updates as you type, and the swap button flips the direction so you can go from binary back to decimal just as quickly.
Frequently asked questions
How do you convert decimal to binary?
To convert decimal to binary, repeatedly divide the number by two and read the remainders from bottom to top. For example, 10 in decimal is 1010 in binary. The converter above does it instantly — type a decimal value on the left and the binary result appears on the right, and you can type in either box to convert in the opposite direction. It only accepts valid digits for each base, so a stray character simply clears the result rather than giving a wrong answer.
What is 10 in binary?
10 in decimal equals 1010 in binary. The conversion table on this page lists common values — 1 is 1, and it continues up to 256 = 100000000 — so you can read off everyday values at a glance. Any value in between converts exactly too, because the tool carries the full number rather than the rounded figures printed here.
What is the difference between binary, decimal and hexadecimal?
They are just different bases — different numbers of digits before you carry over. Decimal (base 10) is the everyday system with digits 0–9. Binary (base 2) uses only 0 and 1, which is how computers store everything at the hardware level. Hexadecimal (base 16) uses 0–9 then A–F, and is a compact way to write long binary values because each hex digit maps to exactly four bits. The same quantity can be written in any base; only its notation changes.
Is this decimal to binary converter free and accurate?
Yes — it is completely free with no sign-up, and it converts exactly using the standard positional method, validating that every digit is legal for its base. Handy for programming, bitmasks and understanding how an everyday number looks to a computer in ones and zeros. Everything runs locally in your browser, so nothing you enter is uploaded or stored. For octal, custom bases and step-by-step breakdowns, the full number base converter handles any base from 2 to 36.
More conversions
Binary → DecimalDecimal → HexadecimalBinary → HexadecimalHexadecimal → BinaryOctal → DecimalDecimal → OctalOctal → BinaryBinary → OctalHexadecimal → OctalOctal → HexadecimalHexadecimal → Decimal Number base converter →