Octal Calculator
Add, subtract, multiply and divide octal (base-8) numbers online, with decimal results shown alongside. Free, fast and private.
Your result will appear here.
How to use Octal Calculator
- Enter two octal numbers using digits 0–7 only.
- Choose add, subtract, multiply or divide.
- Click Calculate to see the octal and decimal result.
Note: this tool runs in your browser. Nothing is uploaded.
Frequently Asked Questions
Is this tool free?
Yes, it is 100% free with no sign-up. Your data stays in your browser.
Do I need to install anything?
No. It works in any modern browser on phone, tablet or computer.
Is my data uploaded?
No. This tool runs entirely in your browser and your input is never uploaded to a server.
Where is octal used?
Octal is used in Unix file permissions (chmod) and in some older computing systems. Each octal digit maps neatly to three binary bits.