How Does A Laser Distance Measurer Work?

About the distance measurer

Ever heard of a laser distance measurer? No? Alright, well, imagine a tape measure. The concept is pretty easy – a very long, labeled tape is rolled together into a container with a hooking mechanism, allowing you to hook the tape onto an object, and unroll it to reveal the distance between the object and wherever you decide to stand. Now, imagine the same thing, but with lasers.


Alright, maybe that’s a bit of a huge leap from one concept to another, so I’ll go a bit more in-depth and explain how a modern-day laser distance measurer works. Ahem.

What is it?

A laser distance measurer is a tool usually used in carpentry, by contractors, architects, flooring professionals and in real estate. It’s also used in other forms by golfers, archers, and even forestry professionals when taking inventory.


However, no matter what industry you talk about, the basic principle behind the laser distance measurer remains – it takes note of the distance between it and the nearest object in its line of sight using a laser, and the natural reflection of whatever object the laser distance measurer hits with its laser.

How it works

The laser, being a concentrated beam of pure light, is then “caught” by the measuring device, and the split (split [split]) nanosecond that it took for that light to travel to the object and back is calculated via the laser’s optical pulse – depending on how long it took for the laser to get back to the measurer, it’ll tell you exactly how far the reflecting object is.

Because the entire device is built upon reflection, measurements have to be really exact – meaning you can’t afford to hit the wrong target erroneously as that would give you an inaccurate reading, or at least one you wouldn’t want.


Some industries employ a special laser distance measurer – for example, one with an anti-leaf filter, so you can measure the distance between trees without having to find an angle that avoids all foliage. One type of laser distance measurer is specifically designed to hit and locate the distance between the user and a moving object, updating ceaselessly to give accurate readings of distance.

Its limitation

However, what most people don’t realize is that a laser never remains concentrated – light disperses, and very quickly so. Because of that, there are limits to how far a laser distance measurer can actually work – some will measure an object only about half a kilometer away or less.


whereas other (specifically military) models are designed to measure the distance of an object as far away as ten kilometers with an accuracy discrepancy of maximally 5 meters more or less.

But for the average carpenter, or even hobbyist archer, ten kilometers is a bit of an overkill. A laser distance measurer nowadays often comes equipped with a rugged, rainproof body and simple display – all within a machine about the size of a small cellphone. Some laser distance measurers can be as small as four inches, fitting comfortably in your pocket. is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Certain content that appears on this website comes from This content is provided ‘as is’ and is subject to change or removal at any time without prior notice.