Tool to convert to octal base (base 8) or from octal base. Octal base is mostly used in computer science. Numbers written in octal system use numbers from 0 to 7.

dCode is free and its tools are a valuable help in games, maths, geocaching, puzzles and problems to solve every day! A suggestion ? a feedback ? a bug ? an idea ? Write to dCode!

For complete explanations on how to convert from $ N_1 $ base to $ N_2 $ base, see the base-N conversion tool.

Example:123 in base $ 10 $ (also noted $ 123_{(10)} $) is equal to 173 in base $ 8 $ (also noted $ 173_{(8)} $)

How to convert an octal number?

For complete explanations on how to convert from $ N_1 $ base to $ N_2 $ base, see the base-N conversion tool.

Example:123 in base $ 8 $ (also noted $ 123_{(8)} $) is written 83 in base $ 10 $ (also noted $ 83_{(10)} $)

How to recognize octal numbers?

The octal numbers can not have a digit $ 8 $ or $ 9 $.

In computer science, it is usual to display an initial zero in front of an octal number to indicate that they are written in base-8.

Example: $ 12 $ in base $ 8 $ is sometimes written $ 012 $ to indicate that it is an octal number.

Any reference to the number eight is a clue.

Source code

dCode retains ownership of the online 'Octal System (Base 8)' tool source code. Except explicit open source licence (indicated CC / Creative Commons / free), any 'Octal System (Base 8)' algorithm, applet or snippet (converter, solver, encryption / decryption, encoding / decoding, ciphering / deciphering, translator), or any 'Octal System (Base 8)' function (calculate, convert, solve, decrypt / encrypt, decipher / cipher, decode / encode, translate) written in any informatic language (Python, Java, PHP, C#, Javascript, Matlab, etc.) and no data download, script, copy-paste, or API access for 'Octal System (Base 8)' will be for free, same for offline use on PC, tablet, iPhone or Android ! dCode is free and online.

Need Help ?

Please, check our dCode Discord community for help requests! NB: for encrypted messages, test our automatic cipher identifier!

Questions / Comments

Thanks to your feedback and relevant comments, dCode has developed the best 'Octal System (Base 8)' tool, so feel free to write! Thank you!

Thanks to your feedback and relevant comments, dCode has developed the best 'Octal System (Base 8)' tool, so feel free to write! Thank you!