1560s, "ascertain by computation, estimate by mathematical means," from Latin calculatus, past participle of calculare "to reckon, compute," from calculus (see calculus). It replaced earlier calculen (mid-14c.), from Old French calculer.
The meaning "to plan, devise" is attested from 1650s; hence "to purpose, intend" and "think, guess" (1830), both U.S. idioms. Related: Calculable.
updated on October 30, 2022
Dictionary entries near calculate