optimal

the best possible solution to a problem, often in a technical or mathematical context

the highest level of performance that can be achieved

the best possible state for something to be in, or for an activity to take place

the most effective or favorable balance, for example between two or more different things

the best or most desirable amount or level of something

the most appropriate or effective size for a particular object or purpose

the most efficient or effective way of sharing something among a group

the most effective or suitable distance for a particular purpose