That little symbol—µm—is actually the Greek letter mu (µ) combined with an m. It stands for micrometer. And no, it’s not a tool you use to measure your microwave popcorn. Although, that would be a fun invention.
A micrometer is one-millionth of a meter. Yes, you read that right—millionth. To put that in perspective, a human hair is about 70 micrometers wide. So yeah, we’re talking tiny.
If you ever need to sound smart at a party, drop this: “A single micrometer is 0.000001 meters.” Then watch everyone slowly back away. You’re welcome.
