Synonyms for Misestimates:

v.

•errs (verb)
trips, slips up, goofs, slips, misconstrues, mars, fluffs, fouls up, bungles, Botches, miscalculates, misconceives, misjudges, errs, stumbles, blunders.
•misjudges (verb)
overestimates, underestimates, misreads, mistakes.