Binary to Decimal Converter
Type a binary number below to convert it instantly to decimal, with hexadecimal and octal shown as a bonus.
Binary input
Converted result
How to convert binary to decimal
- Type or paste a binary number into the box on the left — only 0s and 1s are valid.
- The decimal equivalent appears instantly on the right, along with hexadecimal and octal.
- Copy the decimal result with one click.
Understanding binary place values
Binary is a base-2 number system, meaning each digit's position represents a power of two, counting from the right starting at 2⁰ = 1. To convert to decimal, add up the value of each position where the binary digit is 1. For example, the binary number 1010 breaks down as (1×8) + (0×4) + (1×2) + (0×1) = 10 in decimal. This same base 2 to base 10 logic applies no matter how long the binary string is — the tool just automates the addition.
| Binary | Decimal |
|---|---|
| 0001 | 1 |
| 0100 | 4 |
| 1010 | 10 |
| 1111 | 15 |
| 11111111 | 255 |
FAQ
Is this binary to decimal converter really free, with no sign-up?+
Yes. The tool runs entirely with JavaScript in your browser — there's no account, no API key, and no limit on how often you can use it.
How does binary to decimal conversion work?+
Each binary digit represents a power of two based on its position, counting from the right starting at 2 to the power of 0. The decimal value is the sum of the powers of two where the binary digit is 1.
What characters are valid input?+
Only the digits 0 and 1 are valid in a binary number. Spaces between digits are ignored, but any other character will show a validation message.
Is there a limit to how large a binary number I can convert?+
The converter handles binary numbers up to 53 bits reliably, which covers every practical everyday use. Extremely long binary strings beyond that may lose precision due to how JavaScript represents large numbers.
Can I also see the hexadecimal and octal equivalent?+
Yes, the result panel shows the decimal, hexadecimal, and octal equivalents of your binary input at the same time.
Tools for Number Conversion
How This Converter Works
Your value is converted live from binary to decimal, hexadecimal, and octal with JavaScript using the standard conversion formulas — nothing you enter is uploaded to a server or stored anywhere.
Last updated: August 28, 2026.
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