To recalculate means to figure something out again, usually because new information has arrived or because you think your first answer might be wrong. When you recalculate a math problem, you work through it a second time to check your answer or to correct a mistake.

You might need to recalculate when circumstances change. If you're planning a road trip that should take six hours, but you hit unexpected traffic, you'd recalculate your arrival time. When a scientist gets surprising results from an experiment, she'll recalculate her measurements to make sure everything is accurate.

Modern GPS devices recalculate your route automatically when you miss a turn, quickly figuring out a new path to your destination. That's actually where many people hear this word most often: “Recalculating!” announces the device as it works out a fresh route.

Sometimes recalculating confirms that your original answer was correct. Other times it reveals an error that needs fixing. Either way, recalculating is about taking a second, careful look at your work to be certain you've got it right.