MISCALCULATE
miscalculate, misestimate
(verb) calculate incorrectly; “I miscalculated the number of guests at the wedding”
miscalculate, misestimate
(verb) judge incorrectly; “I had misestimated his determination”
Source: WordNet® 3.1
Etymology
Verb
miscalculate (third-person singular simple present miscalculates, present participle miscalculating, simple past and past participle miscalculated)
To calculate incorrectly.
To make a gross error in judgement.
Source: Wiktionary
Mis*cal"cu*late, v. t. & i.
Definition: To calculate erroneously; to judge wrongly.
– Mis*cal`cu*la"tion, n.
Source: Webster’s Unabridged Dictionary 1913 Edition