Octal to Decimal Converter
Convert octal numbers to decimal instantly, with no size limit.
Converts live as you type, entirely in your browser using arbitrary-precision math — no size limit and nothing is sent anywhere.
Need the opposite? Use Decimal to Octal Converter
What is Octal to Decimal Converter?
Paste an octal (base 8) number and get its decimal equivalent instantly — octal is used in older Unix file permission notation (like chmod 755) and some legacy systems. Conversion happens live in your browser as you type, using arbitrary-precision math, so it stays accurate even on unusually long octal strings.
FAQ
Digits 0-7 only. Any 8, 9, or non-digit character makes the input invalid.
Most commonly in Unix/Linux file permission notation, e.g. chmod 755, where each digit represents a permission set in base 8.