Octal to Decimal

Enter an octal number and convert it to decimal, hexadecimal, and binary. Results appear instantly in your browser.

Octal
Valid: 0-7 only
Decimal (Base 10)
Result will appear here
Hexadecimal (Base 16)
—
Binary (Base 2)
—
Quick Reference
0→0
1→1
7→7
8→10
15→17
16→20
64→100
255→377
493→755
511→777

Octal to Decimal Converter

This tool converts octal (base 8) numbers into their decimal (base 10), hexadecimal (base 16), and binary (base 2) equivalents. It is useful for working with Unix file permissions, legacy systems, or any context where octal notation is used.

The conversion runs entirely in your browser using JavaScript's BigNumber library for precision.

How to use

  1. Type or paste an octal number into the input field (e.g. 377 or 755).
  2. Click Convert to see the decimal, hexadecimal, and binary results.
  3. Use the Copy button to copy the decimal result to your clipboard.
  4. Click Clear to reset all fields.

What is octal?

Octal is a base 8 number system that uses the digits 0 through 7. Each octal digit represents exactly three binary digits, making it a convenient shorthand for binary values. It is commonly seen in Unix file permissions (e.g. chmod 755) and some legacy computing contexts.

Example

Octal:       377
Decimal:     255
Hexadecimal: FF
Binary:      11111111