Mis-calculate means to make an error in calculating. The antonyms for mis-calculate could be accurately calculate, correctly calculate, or precisely calculate. When someone mis-calculates, they get the wrong answer due to a mistake in their math. Accurately calculate means to calculate something correctly, without any mistakes. Correctly calculate means to calculate something in a way that is correct, with no errors. Precisely calculate means to calculate something with great accuracy and attention to detail, making sure that everything is correct. These antonyms can be used to describe someone who is good at math and has a talent for calculating numbers correctly.