Optimum vs Optimal

Optimum vs Optimal

There are pairs of words in English that have similar meanings or are synonymous yet confuse people as to which one of them has to be used in a given context. One such a pair of words is optimum and optimal. Both words refer to a condition or the amount or degree of something that is sufficient or desirable or ideal. Both words are adjectives and convey the same meaning; for example, when we say that the conditions were optimum or optimal for the growth of the organism. Because of their overlapping, optimum and optimal are words that are hard to differentiate. This article attempts to highlight the differences between optimum and optimal.


Optimum is an adjective that tells that conditions are almost perfect, the best, or the most satisfactory for achieving a good result. If a lady asks her gynecologist what the optimum age for childbearing, she is interested in knowing the age around which she should plan to conceive and give birth to a child. To talk about finding an optimum solution to an environmental problem is to find a solution that is not just acceptable to all, but also one that hurts the environment the minimum.

Optimum can also be used as a noun. Optimum conditions, when they exist, mostly lead to favorable results.


The word optimal refers to best possible conditions that can happen to be there when a favorable outcome occurs. Optimal refers to best or ideal conditions that lead to a favorable outcome. However, ideal is unattainable in most instances, and this is why there is optimal that is the next best after ideal. So we talk about optimal conditions and not ideal. So when the temperature is best, at least for the moment, we say it is optimal for a particular machine to work efficiently, and not ideal.

Optimal is always used as an adjective and never as a noun.

Optimum vs Optimal