Decimal to Octal Converter

A decimal to octal converter turns an everyday decimal number into an octal number, made of digits from 0 to 7. Octal is still used in file permissions, embedded systems and computing study, so students and developers meet it often.

The method is repeated division by 8. You divide by 8, write down the remainder, then divide the quotient again, until the quotient reaches 0. Reading the remainders from last to first gives the octal answer. This tool does those steps for you and shows them, so you can check every step.

Everything runs in your browser, so your number never leaves your device. The tool handles whole numbers exactly, with no rounding and no sign up.

Worked example: decimal 42 to octal

Divide 42 by 8. The quotient is 5 and the remainder is 2. Write down 2.

Divide 5 by 8. The quotient is 0 and the remainder is 5. Write down 5.

Read the remainders from last to first: 52. So 42 in decimal is 52 in octal.

You can check the answer by place value: 5 times 8 plus 2 equals 42.

How to Use This Tool

1. Enter a decimal number as a whole number.
2. Press Convert to see the octal result and the division steps.
3. Copy the result or download it as a text file.
4. Use Load Sample to try 42, which converts to 52.

Why Use This Tool

• Exact for long decimal values, with no rounding and no sign up.
• Shows every division step, so the answer is easy to verify by hand.
• Rejects fractions with a plain error message, since this tool converts whole numbers only.
• Private by design, since nothing leaves your device.

Common Values

Related Conversions

If you need a different direction, try the Decimal to Binary Converter, Decimal to Hex Converter, Octal to Decimal Converter and Binary to Octal Converter. Each one works the same way, in your browser, with the steps shown so you can check the answer.

Frequently Asked Questions