misestimate

from WordNet (r) 3.0 (2006)

misestimate
    v 1: judge incorrectly; "I had misestimated his determination"
         [syn: {miscalculate}, {misestimate}]
    2: calculate incorrectly; "I miscalculated the number of guests
       at the wedding" [syn: {miscalculate}, {misestimate}]

from The Collaborative International Dictionary of English v.0.48

Misestimate \Mis*es"ti*mate\, v. t.
   To estimate erroneously. --J. S. Mill.
   [1913 Webster]