When it comes to expressing mental abilities, different words might suit the purpose better than the somewhat uncommon "mental calibers." Some of the synonyms that could replace "mental calibers" include "intellectual capacity," "mental prowess," "cognitive aptitude," or "brain power." Using these synonyms might help create a more vivid and relatable impression, as they entail similar meanings but may resonate with a broader audience. Mental agility, mental competence, or intellectual acuity are other options that could be used interchangeably with "mental calibers" depending on the context of the sentence or text. These synonyms are useful in describing someone's mental capabilities or intelligence and might add a level of interest or clarity to the description.