To be exact means to be completely accurate and precise, with no room for error or approximation. When your teacher asks for an exact answer to a math problem, she wants 3.14159, not “about three.” When a recipe calls for an exact measurement of baking soda, even a small difference can ruin your cookies.

The word suggests careful attention to details that matter. A scientist conducting an experiment needs exact measurements. A jeweler cutting a diamond needs exact angles. These situations demand precision because small differences create big consequences.

People also use exact to emphasize getting something completely right. You might say “That's the exact same backpack I have!” or “Those were her exact words.” Here you're stressing that something matches perfectly, not approximately.

As a verb, to exact means to demand and obtain something, often with force or authority. A king might exact tribute from conquered territories. A difficult climb exacts a toll on even experienced hikers. This meaning carries a sense of taking or requiring something, usually something costly or difficult.

Someone who is exacting sets very high standards and demands precision from others.