Decimal ↔ Binary Converter
Enter a decimal number to convert to binary, or a binary number to convert to decimal. The result will appear in the other box.
Binary is a base-2 number system, meaning it only uses two digits: 0 and 1. Each position in a binary number represents a power of 2, starting from 2 0 (which is 1) on the rightmost side.
For example, the binary number 1101 is calculated as:
1 × 2^3 + 1 × 2^2 + 0 × 2^1 + 1 × 2^0 = 8 + 4 + 0 + 1 = 13 (in decimal).
How to use Decimal ↔ Binary Converter
- 1
Enter a number
Type a decimal number into the Decimal Value box, or a binary number into the Binary Value box.
- 2
See the conversion
The matching result appears instantly in the other field as you type, with no button to press.
- 3
Review the steps
Check the Conversion Steps section to follow the division-by-2 process that produces the binary result.
- 4
Copy the result
Use Copy Decimal or Copy Binary to grab the value, or Swap to reverse the conversion direction.
Frequently asked questions
Does it convert both directions?
Can I see how the conversion is calculated?
What counts as valid binary input?
Is there a limit on how large a number can be?
Is my data kept private?
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