Calculator
What the Octal Converter does
Octal Converter: converts Status, Decimal and Binary from Number and From base. Example: number 377 and from base Octal gives status Converted.
The Octal Converter takes Number and From base and returns Status, Decimal and Binary. You can nudge a single number and watch the effect straight away.
Most people who open the Octal Converter are people inspecting an API response. Most of these tasks are one-liners in a terminal, but not when you are away from one.
Because it is all local, the tool is as fast as your device and as private as your own notes.
Further down the page: what each field expects, how the result is derived, and one example worked from the defaults.
What do the Octal Converter fields mean?
The Octal Converter uses 2 inputs. Pre-filled inputs double as documentation: each one shows what a reasonable value looks like.
| Field | What to enter | Default |
|---|---|---|
| Number | required | 377 |
| From base | choose from Decimal, Binary, Octal or Hex | Octal |
How does the Octal Converter work?
Each output is derived from the inputs above in a single pass; there is no hidden state carried between runs, so the same inputs always give the same conversion.
Checks happen up front, so errors surface next to the form instead of hiding in the output.
Worked example
These are the values the Octal Converter loads by default, and the result it produces from them. This is the worked example the page starts from, reproduced here so you can check the arithmetic.
| Number | 377 |
|---|---|
| From base | Octal |
| Status | Converted |
|---|---|
| Decimal | 255 |
| Binary | 11111111 |
| Octal | 377 |
| Hex | FF |
| All bases | dec 255 bin 11111111 oct 377 hex FF |
Base 8
Octal groups binary into threes rather than fours. It largely predates hexadecimal and survives mainly in Unix file permissions.
| Digits | 0 to 7 | eight symbols |
|---|---|---|
| Place values | … 512, 64, 8, 1 | powers of 8 |
| Example | 755₈ | 7 × 64 + 5 × 8 + 5 = 493₁₀ |
| One octal digit | = 3 binary digits | 7₈ = 111₂ |
Worth knowing
- chmod 755 is octal: each digit is three permission bits (read (4), write (2), execute (1)) for owner, group and others.
- Octal was popular on machines with word sizes divisible by three, such as the 12-bit and 36-bit systems of the 1960s.
- A leading zero means octal in C and older JavaScript, which has caused a long history of subtle bugs.
How to use it
- Put Number.
- Pick a value for From base: the options are Decimal, Binary, Octal or Hex.
- You will see the result move while you are still editing: that is expected.
- The results panel then shows Status, Decimal, Binary, Octal, Hex and All bases.
- Copy Link puts the current inputs in the URL, so bookmarking it brings the same numbers back.
What this tool does not do
- Output follows the common convention for this format; a specific toolchain may have its own house style.
- Processing happens in your browser, so extremely large inputs are bounded by available memory.
- Nothing is saved between visits, so keep your own record of anything you need again.
Frequently asked questions
2 things: Number and From base. Every box already holds a working value, which makes it easy to isolate the effect of a single variable.
With the values loaded when the page opens, status comes out as Converted. The figure is derived from the inputs above, so it updates whenever they do.
It is not stored or transmitted. The calculation happens locally and leaves no trace with us.
No. There is no account, no usage cap and no trial period. The site is funded by advertising rather than by charging for the tools.
It implements the published definition directly, without shortcuts or approximations.