The Collaborative International Dictionary of English v.0.48:

Calculation \Cal`cu*la"tion\ (-l[=a]"sh[u^]n), n. [OE.
   calculation, fr. L. calculatio; cf. OF. calcucation.]
   1. The act or process, or the result, of calculating;
      computation; reckoning, estimate. "The calculation of
      eclipses." --Nichol.
      [1913 Webster]

            The mountain is not so his calculation makes it.
                                                  --Boyle.
      [1913 Webster]

   2. An expectation based on circumstances.
      [1913 Webster]

            The lazy gossips of the port,
            Abhorrent of a calculation crost,
            Began to chafe as at a personal wrong. --Tennyson.
      [1913 Webster]

WordNet (r) 3.0 (2006):

calculation
    n 1: the procedure of calculating; determining something by
         mathematical or logical methods [syn: calculation,
         computation, computing]
    2: problem solving that involves numbers or quantities [syn:
       calculation, computation, figuring, reckoning]
    3: planning something carefully and intentionally; "it was the
       deliberation of his act that was insulting" [syn:
       calculation, deliberation]