How Does a Laser Range Finder Work? [EXPLAINED in Detail]

Laser Range Finder

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A laser rangefinder is an optical device that uses laser technology to measure distances accurately. Laser rangefinders are widely used in many applications, including surveying, construction, wildlife observation, hunting, and even golfing. 

Most of the laser rangefinders that you’ll find available for purchase, particularly for hunting, are going to utilize the same technology and be largely similar in most respects, but there are some important differences to keep in mind that may affect which rangefinder you purchase.

We’ll cover those here in this article, as well as explain how a laser rangefinder works.

How Exactly Does a Laser Rangefinder Work?

How Exactly Does a Laser Range Finder Work?

A laser rangefinder emits a laser beam that is reflected off a target and returns to the rangefinder. The time taken by the laser beam to travel to the target and back is used to calculate the distance to the target. This distance measurement is then displayed on the rangefinder’s screen.

Technical Details

A rangefinder emits a pulse and then tracks how long it takes that pulse to be detected by the sensor. Since the speed of light is so fast, the technology inside the rangefinder needs to be quite sophisticated for it to provide any degree of accuracy. Therefore, you shouldn’t expect your rangefinder to get you more than within a meter or so of the actual distance. And they also replaced old optical rangefinder.

For hunting, this is fine, since 99.9% of us aren’t going to be adjusting for the drop from 100 yards to 101 yards, for example.

In push-button mode, the rangefinder sends a single laser light pulse and calculates based on that. In scanning mode, it will emit a continuous set of pulses and keep refreshing the ranging info based on the latest laser pulse.

It may be counterintuitive to think of the laser bouncing back to the rangefinder since you might think you need to shoot laser beams at a reflective surface with incredible precision to get that to happen, but that is not the case. When the laser beam hits the surface of the object’s laser pointer, the laser light scatters, and laser beam reflects in all directions so it gets difficult for laser rangefinders to track the distence.

This is why you can see where the laser beam is landing; a portion of the concentrated ambient light is reflecting into your eye. Laser rangefinders work in exactly the same way.

Much like your eyes, a rangefinder will have a limited effective range as well, where there simply isn’t enough of the laser light bouncing back into the sensor to get an accurate measurement. 

Factors to Consider When Buying a Laser Rangefinder

1. Magnification


The magnification of a laser rangefinder refers to the level of enlargement of the target image. A higher magnification allows for a clearer and larger image, making laser rangefinders easier to range a target accurately.

When purchasing a rangefinder, it is important to consider the type of activity it will be used for and choose a magnification that is suitable for the task at hand. 

The most common magnifications I’ve seen are 5x and 6x, which seem to be a pretty good balance. You won’t need a rangefinder unless you’re trying to hit something a ways out, so you probably wouldn’t want to go less than 4x, but more than 6x magnification starts to make laser rangefinders difficult to quickly acquire the target and get a good reading on it.

If you know for sure that you will only ever be using the rangefinder for targets 500 yards out and further, it may be worth trying to find a rangefinder that has more than 6x magnification, but other than that, I’d recommend sticking with the typical. 

2. Effective Range

Effective Range

The effective range of a laser rangefinder refers to the maximum distance at which it can accurately measure distances. It is important to consider the effective range of a rangefinder when purchasing one, as laser rangefinders with a short effective range may not be suitable for all the situations you might find yourself in.

Vortex Optics Crossfire HD 1400 Laser Rangefinder

The most effective ranges that I see are between 700 and 1000 yards, and even pricey laser rangefinders like the Vortex Crossfire HD 1400 will say that it’s effective out to 1,400 yards but only effective for game out to 750 yards. The effective range of laser rangefinders can be a real limiting factor depending on what you’re doing.

700 yards, for example, isn’t that far out for LRP shooters and can even be within the realm of possibility for experienced big-game hunters, so getting a rangefinder that can be reliable as far out as you need it is an important thing to make sure of.

3. Accuracy

Effective Range

Accuracy refers to how close the distance measurement is to the actual distance. Most laser rangefinders that are designed for hunting should be giving you accurate readings, give or take 1 yard or possibly 2. The accuracy will go down the further you’re aiming, but not as much as you might think and not enough to be a big deal in most cases.

It’s important to check the reviews on the ranger you’re considering to see if other users have had issues. It is important to consider the accuracy of a laser rangefinder when purchasing one, as a rangefinder with low accuracy may not provide the necessary level of precision for certain activities.

4. Customer Service/Warranty

When purchasing a laser rangefinder, it is important to consider the level of customer service and warranty provided by the manufacturer. Stuff goes wrong, and even companies with great quality control can ship out lemons every now and then. With something that needs to be as precise as a rangefinder, if something isn’t functioning properly, the entire unit may be useless.

Some companies have a lifetime warranty, while others only have it for a few years. It’s up to you whether you want to prioritize a better warranty and are willing to pay the extra cost.

5. Modes of Operation

Horizontal Distance Mode

The horizontal distance mode is a mode in which the rangefinder measures the horizontal distance to a target. This mode is the most useful for hunting, where the distance to the target is more important than the height difference between the rangefinder and the target. Let me explain a bit more.

Unless you and your target happen to be at the exact same elevation with no change in between, then the line-of-sight between you is going to be the hypotenuse of a triangle where the horizontal distance and vertical distance are the other two legs. You might think that line-of-sight is what you want anyway, but that’s usually not the case.

Usually, you’re adjusting your elevation on laser rangefinders based on how much the bullet is going to drop as it travels. The vertical distance between you and your target won’t affect this much unless it’s a drastic difference. What matters more is how far horizontally the bullet has to travel, and that’s what you need to base your adjustments on.

Gogogo Sport Vpro Laser Golf/Hunting Rangefinder, 6X Magnification Clear View 650/1200 Yards Laser Range Finder, Lightweight, Slope, Pin-Seeker & Flag-Lock & Vibration (650 Yard)

You absolutely need to know if your rangefinder is giving you horizontal distance or line of sight. You cannot properly use a rangefinder unless you know which reading it is giving you. Some laser rangefinders have other names for this mode, like Gogogo’s Sport VPRO calls it “Slope distance correction”.

Line of Sight Mode

The problem with horizontal distance modes is that they can interfere with ballistic calculators or a dope sheet made using the line of sight difference. If you have already accommodated for the difference, then your rangefinder accommodating for it again can mess up your shot.

Enter line of sight mode. The line of sight mode is a mode in which the rangefinder measures the straight-line distance to a target. This mode allows you to use other tools to calculate the needed drop and just gives you a straight-line distance from you to the target.

Vortex Optics Crossfire HD 1400 Laser Rangefinder

Another good use case for line of sight mode is when the difference in elevation is significant. Vortex states that LOS mode is recommended when you are shooting further than 500 yards with a slope that is greater than 15 degrees. 

Scanning Mode

The scanning mode is laser beam a mode in which the rangefinder continuously measures distances to multiple targets. This mode is useful anytime multiple distances need to be measured quickly. A good example is when you’re tracking an animal from a few hundred yards away, but it’s running for reasons unrelated to you.

You don’t know when it will stop, and when it does, you may only have a moment to take your shot. In a case like that, it may be beneficial to already have an accurate reading thanks to the continuous scanning.

6. Measuring More Than Just Distance?

Many laser rangefinders will do more for you than just spit out a measurement of distance between you and your target. They can also measure the speed of a moving target, provided you can keep your laser beam on the target as it moves.

Assuming the rangefinder has a horizontal distance mode, you should also be able to see how steep the slope is between you and the target.

7. Price

The price of a laser rangefinder can vary greatly depending on the features it provides and the brand of the company offering it. I feel quite comfortable recommending against most laser rangefinders that are cheaper than $50, but you may find one that has stellar reviews and everything you need. You can also see prices as high as $200 or even more.

The old adage of “you get what you pay for” applies here to a certain extent, but the core functionality between the high-rated laser rangefinders that are only $60-$80 and the high-rated laser rangefinders that are $200 is not greatly different.

The main differences you’ll notice are consistency and performance in a wider variety of less-than-ideal circumstances.

8. Rechargeable vs. Replaceable Batteries

Laser rangefinders can be powered by either rechargeable batteries or replaceable batteries. This is a matter of preference. Battery life tends to be better with rechargeable batteries, but they can also go bad over time, so it depends on your priorities.

Benefits of Using a Laser Rangefinder

Eliminate Guesswork

Using a laser rangefinder can eliminate the need for guesswork when measuring distances. With a rangefinder, the distance to the target can be measured accurately and quickly, so rather than just eyeballing it and hoping for the best, you can either dial or hold for exactly the distance that you’re shooting at.

Guesswork can cause you to miss a lot of important shots, even if you think you have a pretty good eye.

Improve Accuracy

Beyond guesses, a laser rangefinder can improve accuracy over other methods like counting your paces or even dragging a tape measure out to the target.

Those methods are obviously only useful when target shooting anyway, but a rangefinder can give you more precise readings than either of those two methods, allowing you to get more accurate shot placements.

Improve Chances of A First Shot Hit

In hunting, the first shot is usually the most important. Often your first shot is the only shot you get at an animal. Knowing the exact distance to the target and being able to either hold or dial to where you need to be gives you a much better chance of landing that very first shot.

When you’re at the range, this is less important since you can just adjust your aimpoint as you go.

Rangefinders that also give you the speed of a moving target and other data can also help you hold for windage and further improve your chances at hitting it.

Get Other Shooting Info

Some laser rangefinders can provide additional information such as angle range compensation, vertical distance change, and speed of a moving target, which can be useful for several reasons while you’re hunting. If you’re willing to drop an obscene amount of money on your rangefinder, you can even get something like the Trijicon Ventus, which will also give you wind measurements.


How Does a Military Rangefinder Work?

A military laser rangefinder work similarly to a standard laser rangefinder but may have additional features and capabilities specific to military use. It typically uses laser beam technology to accurately measure distances to targets and will have a longer effective range and tighter accuracy than a standard rangefinder.

Are Laser Rangefinders Good?

Laser rangefinders can be good, providing accurate and quick distance measurements. That said, the quality of a laser rangefinder can vary a lot depending on the manufacturer and the features it provides. Always compare your needs and budget with the quality available when purchasing a laser rangefinder.

How Far Can Laser Rangefinder Work?

Most rangefinders for hunting will get you out somewhere between 600 and 1000 yards depending on the application. The more reflective the target, the closer it will need to be in order for the rangefinder to get an accurate reading. Because reflected light will provide good data This is because a reflective surface won’t scatter as much of the light and will instead keep it in a tight laser beam.


A laser rangefinder is a useful and versatile tool that uses laser beam technology to measure distances accurately. When purchasing a laser rangefinder, it is important to consider the magnification, effective range, accuracy, customer service/warranty, modes of operation, and price. 

Whether you actually need a laser rangefinder is up to you, but a laser rangefinder can eliminate guesswork, improve accuracy, and provide additional shooting information. It can be a valuable tool, especially for hunting, but even for target and competition shooting.

If you have a favorite rangefinder that you can recommend, feel free to drop it in the comments.

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