Decimal to Octal Converter

Convert any decimal number to octal (base 8), binary and hexadecimal — with the step-by-step division method shown.

What Does This Tool Do?

Convert any decimal number to octal (base 8) with the repeated division-by-8 method shown step by step. Also shows binary and hexadecimal equivalents.

Key Features

8️⃣
Base 8 Output
Octal with 0o prefix.
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Division Steps
Div-by-8 method clearly shown.
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3 Bases
Octal, binary and hex together.
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Copy
One-click copy of octal result.

How to Use

  1. Enter any non-negative decimal integer.
  2. Octal, binary and hex appear instantly.
  3. Read the division steps to understand the process.

Frequently Asked Questions

How do you convert decimal to octal?▾
Divide by 8 repeatedly, recording the remainder (0–7) each time. Read remainders from bottom to top. E.g. 255 ÷ 8 = 31 r7, 31 ÷ 8 = 3 r7, 3 ÷ 8 = 0 r3 → 0o377.
Why is octal used in computing?▾
Octal groups binary digits in sets of 3 (since 2³ = 8), making it a compact representation of binary. It was widely used in early computing and Unix file permissions still use octal (e.g. chmod 755).
What does 0o mean?▾
0o is the Python/modern prefix for octal literals, just as 0x means hexadecimal. Some older systems use a leading zero (e.g. 0377).