Number Base Converter
Convert numbers between binary, octal, decimal and hexadecimal.
| Base | Value |
|---|---|
| Binary | 1010 |
| Octal | 12 |
| Decimal | 10 |
| Hexadecimal | A |
This number base converter changes a whole number between binary (base 2), octal (base 8), decimal (base 10) and hexadecimal (base 16). Type a value, pick the base it is written in and the base you want, and the converted result appears instantly together with a table showing the number in all four bases.
The conversion works by reading your input in its source base to get its plain decimal value, then re-expressing that value in the target base. Only digits that are valid for the source base are accepted — 0 and 1 for binary, 0 to 7 for octal, 0 to 9 for decimal and 0 to 9 plus A to F for hexadecimal — so an invalid entry shows a dash instead of a result.
How to use it
- 1Enter the number you want to convert.
- 2Choose the base your number is currently written in.
- 3Choose the base you want to convert to.
- 4Read the converted value, and use the table to compare the number across binary, octal, decimal and hexadecimal.
Frequently asked questions
What is 1010 in binary as a decimal number?+
Binary 1010 equals decimal 10. Reading right to left, the set bits are worth 2 and 8, and 2 + 8 = 10.
Why is my entry showing a dash?+
The value contains a digit that is not valid for the selected from-base. For example, the digit 2 is not allowed in binary and the letter G is not allowed in hexadecimal. Remove the invalid character to see a result.
What are the valid digits for each base?+
Binary uses 0 and 1, octal uses 0 through 7, decimal uses 0 through 9, and hexadecimal uses 0 through 9 plus the letters A to F.
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