When discussing rangefinders, and how well they work, you may have heard the term Beam Divergence. What is Beam Divergence? Why is that something you need to consider when you’re out shopping for a shiny new laser rangefinder? We’re going to go over what beam divergence is, how to do the math to see what size the beam will be at a given distance, and some common numbers for rangefinders on the market. In essence the Beam Divergence is a way of measuring the size of the beam at a given distance, very similar to how you measure and rank group sizes. There are other factors that determine the level of performance you will get out of a laser rangefinder, and we’ll discuss a few of those as well!