Octal to Decimal Converter
Enter an octal number to convert it to decimal. Octal is used in Unix file permissions, legacy computing, and digital systems.
Octal to Decimal
Base 8 → Base 10
0o
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How to Use the Octal to Decimal Converter
1
Enter an octal number (e.g. 755).
2
Click Convert.
3
View the decimal equivalent.
Frequently Asked Questions
What is the octal number system?
Base 8, using digits 0-7. Each octal digit represents 3 binary bits.
Where is octal used?
Unix/Linux file permissions (chmod 755), some older computing systems, and digital electronics.
How does octal-to-decimal work?
Multiply each digit by 8 raised to its position power and sum. 755 octal = 7x64 + 5x8 + 5x1 = 493.