Binary Calculator
Convert a number between binary and decimal, in either direction.
- Free to use
- Accurate results
- No registration required
- Works on all devices
Enter a number and choose a direction to convert between binary and decimal.
Enter a decimal number, or a binary number using only 0s and 1s, depending on the direction chosen below.
Your result
11111111
Result
AI explanation
Formula
Repeated division/multiplication by 2 to convert between decimal and binary place valuesWorked example
Decimal 255 to binary
| Field | Value |
|---|---|
| Value | 255 |
| Convert | from-decimal |
| Result | 11111111 |
Assumptions
- Only non-negative whole numbers are supported.
- Binary input must contain only the digits 0 and 1.
Frequently asked questions
How does binary (base 2) work?
Binary uses only two digits, 0 and 1, with each position representing a power of 2 (1, 2, 4, 8, 16, ...) — the same way decimal positions represent powers of 10.
Why is binary used in computing?
Computer hardware represents data using two physical states (like "on" and "off"), which map naturally onto binary's two digits.
What if I only need one direction?
Use the Decimal to Binary Calculator or Binary to Decimal Calculator for a single-purpose version of this same conversion.