To calculate means to figure out an answer using math or careful reasoning. When you calculate how much money you need to buy three candy bars at $1.50 each, you're working out the total: 3 times $1.50 equals $4.50.

Before calculators and computers existed, people calculated using their minds, paper and pencil, or tools like the abacus. Today, we still calculate mentally for quick problems, but we also use calculators and spreadsheets for complex math. Scientists calculate the speed of rockets, engineers calculate the strength of bridges, and your teacher calculates your grades by adding up your test scores.

You can also calculate things that aren't strictly mathematical. A chess player calculates which moves might work best. A hiker calculates whether there's enough daylight to reach the summit. When you calculate something, you're thinking it through systematically rather than just guessing. Someone described as calculating thinks carefully about consequences before acting, though this word sometimes suggests they're cold or manipulative in how they plan things.