Octal to Decimal Converter

What is the Octal to Decimal Converter?

Convert octal numbers to decimal. Octal values are still common in Unix file permissions, and converting them to decimal helps when reading tools that display both.

How to use the Octal to Decimal Converter

1. Enter your octal number.
2. Results update automatically as you type; you can also press Calculate.
3. Read the output: decimal.
4. Use the 📊 chart to see the result visually, then copy or share it.

Formula and method

Worked example

With octal number = 1363, the Octal to Decimal Converter returns decimal: 755.

Where the Octal to Decimal Converter helps in real life

A script reports file mode 644 and a library function expects the decimal integer instead. Converting gives 420, which you can pass straight to the function.

A student practicing number systems converts several octal values to decimal to check the place-value working in their notebook.

Common mistakes to avoid

• Entering an 8 or 9, which do not exist in octal.
• Forgetting that some languages treat a leading 0 as octal.
• Mixing up octal and decimal values that look the same.
• Reading permission digits as one decimal number.

💡 Practical tip: Octal 755 equals decimal 493, which is why permission numbers look odd in decimal.

Tips for better results

• Remember each octal digit stands for three bits.
• Check the reverse conversion with the decimal-to-octal tool.
• Prefix octal literals clearly in code.

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