optimum or optimal?

Is there a difference between optimum and optimal?

As adjectives, they have the same meaning: best; most favourable; most conducive to a good result

They both come from the Latin optimus, meaning “best”.

Look at these examples:

  • What is the optimum/optimal childbearing age?
  • We need to find the optimal/optimum solution.
  • In our case, the optimum/optimal investment would produce a modest return at no risk.

Optimum can also be a noun, while optimal has two derivatives:

  • optimally (adverb)
  • optimality (noun)
  • Allen says:

    My peers and I use these words in spoken English all the time; however, we are engineers, and therefore quite perverse.

    There is also seems to be some consensus that “optimal” connotates a more subjective or circumstance-based judgement, whereas “optimum” connotates a more objective or universal judgement. See this thread:

    To all of the above, I will also add that my personal experience in the use of either term is that it carries the implication of a condition that is based upon the reconciliation of conflicting requirements or goals, not that it is a perfect synonym for “best”, but that’s just personal experience (with my perverse engineering colleagues); I have not found it documented anywhere.


  • dua says:

    i am still confused

  • faruk says:

    Thanks, i was very confused but i got the actual meaning,

  • joseph says:


  • sara says:

    thank you

  • Justo says:

    I repeat, I find the explanation about optimum and optimal quite good, but again, that word is not widely used in spoken English but in the written one like newspapers and the like.

    Cordially yours,

    Professor Justo Hernández Castell

  • Justo says:

    I found the explanation good, although that word is not widely used in spoken English, it is rather used in written English, one is likely to find it in newspapers and the like.

    Cordially yours:

    Professor Justo Hernández Castell

  • zedda says:

    very good, quiet interesting. you should carry on enhancing our vocabulary with such explanation.

  • Jose Romeu Pioltine says:

    Thanks a lot for the excellent comments.

  • laphinh says:

    thank you it gained me a lot

  • Monalisa says:

    Hi there,

    I was very exciting when reading your explanation and found it very useful. This is a new word to me and I applied it promptly in my writing.

    Thanks for helping us in learning English effectively.

    Please do me a favour as I have to write a proposal but still not know how to structure this document. Please could you give me some advise/instruction on this matter?

    Many thanks with best regards,

  • Jacky Liu says:

    Perfect, that is the first time to clear the two words so much. thanks!

  • zoubir tazia says:

    thanks so much for your information.truely , these words are new for me and i’ll use them in the future .

  • mohamed says:

    That’s great many thanks

  • Fathid says:

    Fathid Both words are alike, they have the same meaning but grammatically optimum is the noun and optimal is the adjective thanking you, I think is not enough for you Mr Josef Essberger you deserve the best regards and also the best, Fathd

  • Bakhtiar says:


  • jalil anti khomeyni says:

    Nice, So pleased I am.

  • sayed says:

    how amazing

  • sayed says:

    how ammazing!
    It is very clear

  • shalva says:

    Thanks a lot for this explanation.

  • Hamon says:

    Very usefull. I sometimes think that they are only adj. So, it’s exciting. Thanks very muc!

  • Linda k hollywood says:

    Very good and excellent verb Optimum and optimal
    is mean best or good level and the verb ” optimist”
    I think is the same meaning verb optimal.

    Good Luck
    Linda kosolsak (Hollywood)

  • leyla says:

    thanks , it’s a new world for me

  • Ricardo Loli says:


  • mahmoud says:

    Thanks a lot

  • vksingh says:

    good difference for esl learner,inhibition in the use of these words is eliminated.

  • sen says:

    Thanks for confirming the equivalence of the two words. Your question put a doubt in my mind and forced me to probe further by clicking ” read further” in the ESL newsletter. Very good question!!

  • Jose Rodolfo says:

    Excelent, thanks a lot.

  • jyoti says:

    thank u

  • João Ghizoni says:

    Thanks a lot, Mr. Essberger. Very clear and straighforward explanation. Congratulations. Would you mind checking these examples?

    – Optimality is the level we should reach before we say we’re able to speak fluently.

    – Speaking English optimally entitles you to communicate wherever you go.

    Examples with ‘optimum/optimal’ you’ve already given, right?
    (João, Florianópolis, SC, Brazil)

  • Abdisalam.O.Mohamud says:

    Thank you indeed Mr.Josef Essberger,Founder
    Iam very grateful to you how you assisted alot of people around the world to learn English Language through Internet.
    So far, I gained alot from this programme of Englishclub, now I am learner of this language but Iam hopeful to be a teacher in the future.
    In addition to that, I advised freinds of mine who are interesting to learn English to join in this Englishclub.
    Thanks again Mr.Josef Essberger.

    On the other hand, the words optimum, optimal.I have not known before, so it is very useful for me to learn them.
    Now I have understood the difference between them.

  • Sara Adam says:

    Great , thanks

  • Fasih says:

    Another addition to my knowledge of English language, thanks for good expaination.

  • NISHA says:


  • Pearl Nguyen says:

    Optimal / Optimum explaination. Thanks.

  • Manit says:

    Good,thanks a lot. I have understood quite well.

  • amelia says:

    thanks… but i am still confuse how to use the derivative of one word. any suggestion?

  • Bahar Sarafrazi says:

    thanks a lot because of your information in this site.that’s wonderful

  • moussa says:

    great, very good, thanks!!!!

  • teresita says:


  • teresita says:


  • Terry says:

    Good! Thanks!

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