Octal to Decimal
Convert octal numbers to decimal instantly. For example, 144 in octal is 100 in decimal.
Octal to Decimal — quick reference
| Octal | Decimal |
|---|
How to use the Octal to Decimal
- Type or paste your octal value on the left.
- Read the decimal result on the right — separate multiple values with spaces.
- Copy the result, or check the reference table below.
About the Octal to Decimal
This tool converts octal numbers to decimal. Octal is base 8, written with the digits 0 through 7; decimal is base 10, written with 0 through 9. Type a value on the left and the decimal result appears instantly, and you can convert several values at once by separating them with spaces.
Worked example. Take 144 in octal. Expand each digit by its place value: 1×8^2 + 4×8^1 + 4×8^0 = 100 in decimal.
Octal still turns up wherever file permissions and a few older systems are concerned, and reading those figures as ordinary base-10 numbers often makes them easier to reason about. The move is exact: an integer written in base 8 and the same integer in base 10 are one quantity in two notations, so nothing is rounded on the way across. Further octal-to-decimal pairs are listed in the table below for a quick manual check, and the calculation is performed locally in the browser, so none of what you enter is transmitted. For the reverse direction use the decimal to Octal converter, or the all-in-one number base converter for arbitrary bases.
Frequently asked questions
What is 144 in octal converted to decimal?
144 in octal equals 100 in decimal. You can confirm it with the worked example above, or by typing 144 into the converter.
Is this octal to decimal conversion exact?
Yes. Converting a whole number between bases changes only how it is written, not its value, so there is no rounding. 144 and 100 are the same quantity expressed in base 8 and base 10.
Can I convert more than one octal value at once?
Yes. Separate each octal value with a space and every one is converted to decimal on its own, in order.
Is my data uploaded anywhere?
No. The conversion runs entirely in your browser with JavaScript; nothing you type is sent to a server.