Binary to Decimal Converter

Paste one or more binary (base-2) strings, like 1010 or 11111111, and read their decimal values instantly.

What is the Binary to Decimal Converter?

The Binary to Decimal Converter reads strings of 0s and 1s and converts each one to its standard base-10 decimal equivalent. It handles binary strings of any length using arbitrary-precision arithmetic, so long values from a 32-bit or 64-bit register convert exactly, without the precision loss ordinary calculators run into.

How It Works

Each entry is checked to contain only the digits 0 and 1, then parsed as a base-2 big integer and rendered as a decimal string. Leading zeros are accepted and simply ignored in the result, the same way they would be if you wrote the number by hand.

Real-World Use Case

Working through a networking or computer-architecture assignment often means converting a subnet mask or register value written in binary, such as 11111111.11111111.11111111.00000000, back to decimal to check your work — this converter does the arithmetic instantly.

Frequently Asked Questions

What characters are allowed in the input?

Only 0 and 1. A space is fine as a separator between multiple values, but within a single value anything besides 0 or 1 makes that entry invalid.

Can I convert several binary numbers in one go?

Yes. Enter each binary value on its own line or separated by spaces, and each one is converted independently, in order, in the result box.

Is there a maximum length for the binary string?

No practical limit — the converter uses BigInt arithmetic internally, so even binary strings representing numbers far larger than a standard 64-bit integer convert accurately.

Need to go the other direction? The reverse converter turns ordinary numbers into binary. Looking for the reverse? Try the Decimal to Binary Converter →