To quantify something means to measure it or express it as a number. When you quantify how much time you spend reading each day, you might say “thirty minutes” instead of just “a lot.” When scientists quantify the speed of a cheetah, they measure it as 70 miles per hour rather than simply calling it “really fast.”

Quantifying helps us be precise and compare things fairly. A teacher might quantify student progress by tracking how many books each student finishes, or how much their test scores improve over the semester. A baker quantifies ingredients: instead of adding “some” flour, the recipe specifies exactly two cups.

Sometimes things are hard to quantify. You can easily quantify your height in inches, but how would you quantify your happiness or courage? Scientists and researchers spend considerable effort figuring out how to quantify things that seem unmeasurable, like the strength of friendships or the beauty of a sunset. When something can't be quantified, we sometimes call it unquantifiable or say it's impossible to put a number on it.