Source : Webster's Revised Unabridged Dictionary (1913)

Calculator \Cal"cu*la*tor\, n. [L.: cf. F. calculateur.]
   One who computes or reckons: one who estimates or considers
   the force and effect of causes, with a view to form a correct
   estimate of the effects.

         Ambition is no exact calculator.         --Burke.

Source : WordNet®

calculator
     n 1: a small machine that is used for mathematical calculations
          [syn: {calculating machine}]
     2: an expert at calculation (or at operating calculating
        machines) [syn: {reckoner}, {figurer}, {estimator}, {computer}]

Source : Free On-Line Dictionary of Computing

calculator
     
        {bitty box}