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Octal Calculator
Add, subtract, multiply and divide octal numbers and convert every result to decimal.
Octal Calculator
Working: —
Result in base 8: —
Decimal check: —
How to use the Octal Calculator
- Enter the first octal value using the digits 0 to 7.
- Choose the operation and enter the second octal value.
- Read the octal result and its decimal equivalent.
Features
- Add, subtract, multiply and divide in base 8
- Digits 0 to 7 only, validated as you type
- Fractional octal values such as 17.4
- Decimal equivalent shown for the result
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Frequently Asked Questions
Common questions about the free online octal calculator.
Enter both values, choose Add and the octal sum appears immediately with its decimal
equivalent.
Only the digits 0 to 7. The digits 8 and 9 do not exist in base 8 and are rejected as invalid
input.
Yes. Choose Subtract and a negative result is shown with a leading minus sign.
Yes. Multiply gives an exact product, while Divide is carried out to the fraction digits you
pick.
It lists each operand and the result converted into base ten so you can sanity check the
octal working.
Yes. Use an octal point such as 17.4. Fractions that repeat are rounded to the digits you
choose.
Whole number arithmetic is exact because the tool uses big integers rather than floating
point numbers.
Yes. Values of dozens of octal digits are handled correctly without losing precision.
Yes. The layout is responsive and works in any modern browser on any device.
Yes. The octal calculator is free, unlimited and needs no account.
Last updated: October 10, 2026