miscalculate
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/ˌmɪsˈkælkjuleɪt/
🇬🇧
/ˌmɪsˈkælkjuleɪt/
To make a mistake in thinking about or planning something.
If you miscalculate how much paint you need, you might have to go back to the store.
To understand a situation incorrectly.
He miscalculated how quickly the project could be completed.