Decimal to Octal Converter
Convert decimal to octal instantly. Free online dec to oct calculator—divide by 8. For Unix permissions and CS study.
How to Convert Decimal to Octal
To convert decimal to octal, repeatedly divide the decimal number by 8 and record the remainders. Read remainders from bottom to top to get the octal representation. This decimal to octal conversion is essential for creating Unix file permissions and working with octal-encoded data.
Decimal to octal: divide by 8, collect remainders, read reverse. Unix file modes (chmod) use octal digits 0–7.
8₁₀ = 10₈.
Unix chmod notation. The table and FAQ on this page walk through the factor if you need it.
Conversion Examples
Example: 8 to octal
- 8÷8=1 r0 → 10 octal
8 decimal = 10 octal
Single digit shift.
Example: 64 to octal
- 64÷8=8 r0, 8÷8=1 r0 → 100
64 decimal = 100 octal
Powers of 8.
Common Use Cases
- Unix chmod notation.
- Legacy systems coursework.
- Digital systems labs.
- Interview practice.
Frequently Asked Questions
How do I convert decimal to octal?
Repeatedly divide by 8; remainders are octal digits (reverse order).
Why octal?
Historically compact for binary groupings (3 bits per oct digit).
What is 10 in octal?
12₈ (1×8 + 2).