Binary to Decimal
Convert a binary number to its decimal value.
About the Binary to Decimal converter
This tool reads a binary number, written only with the digits 0 and 1, and returns its value in everyday base-10. Each position in a binary number is a power of two, so 1011 means 8 + 0 + 2 + 1, which is 11 in decimal. It is useful for understanding how computers count, for electronics and logic exercises, and for checking the output of a decimal-to-binary tool.
How to use it
- Enter a binary number using only 1s and 0s.
- The decimal equivalent appears straight away.
- Copy the result to drop into your notes, code, or calculations.
A common use is decoding a register or flag value back to a familiar number, or verifying a hand-worked conversion. The converter treats the input as an unsigned whole number and handles long bit strings exactly, so 64-bit values convert without rounding. It does not interpret a leading bit as a negative sign. All work happens in your browser, so nothing you enter is uploaded.
Frequently asked questions
How is a binary number converted to decimal?
Each binary digit is multiplied by a power of two based on its position, then the results are summed. For example 1011 is 8 + 0 + 2 + 1, which equals 11.
Does it support signed or negative numbers?
No. The input is treated as an unsigned whole number, so a leading 1 is not read as a negative sign. Two's complement values must be interpreted separately.
Can I convert very long binary strings?
Yes. The tool uses exact integer arithmetic, so long bit strings including 64-bit values convert without losing precision.
Is anything sent to a server?
No. The conversion runs entirely in your browser, so the binary you enter stays on your device.