Octal to Decimal

Your data never leaves your browser

Convert octal numbers (base-8) to decimal (base-10).

Brie — Bug Reporting Tool

Found a bug while testing?

Brie captures screenshots, console logs, network data, and session replays in one click — so developers get the full context without the back-and-forth.

Install Brie — It's FreeLearn more →

About Octal to Decimal

Paste one or more octal numbers (one per line) and get their decimal equivalents instantly. Octal is commonly used in Unix file permissions (e.g. chmod 755) and older computing systems.

How to use

  1. Enter one octal number per line in the input panel.
  2. The decimal equivalent appears instantly in the output panel.
  3. Click Copy to copy the results to your clipboard.

More Number / Base Conversion

Decimal to Octal

Convert decimal numbers (base-10) to octal (base-8).

Octal to Binary

Convert octal numbers (base-8) to binary (base-2).

Binary to Decimal

Convert binary numbers (base-2) to decimal (base-10).

Frequently Asked Questions

FAQs about Octal to Decimal

What is octal?

Octal is a base-8 number system using digits 0–7. It was historically used in computing because three binary digits map cleanly to one octal digit.

Why is octal used in Unix permissions?

Unix file permissions use octal because each of the three permission groups (owner, group, others) maps to a 3-bit binary value (0–7), which is elegantly expressed as a single octal digit.

What is 755 in octal as decimal?

755 octal = 7×64 + 5×8 + 5×1 = 448 + 40 + 5 = 493 decimal.

Can I convert multiple numbers at once?

Yes. Enter one octal number per line and the tool will convert each one individually.

What digits are valid in octal?

Only digits 0–7 are valid in octal. The digits 8 and 9 are not used.