It depends on the target and what rangefinder is being used for. Some manufacturers have estimated that when rangefinders are used with shotguns, the targets are magnified by 10%, this also applies to other types of guns.

How Much Range Does Rangefinder Actually Add
To put it in simple terms, the process of a rangefinder working is called ranging. Rangefinders are devices that measure the distance between an observer and a target and automatically send back a reading with clarity and accuracy to the observer.
While different rangefinders work using different principles, and the different types are used for varying purposes and events, they essentially have one thing in common. Automatic and accurate measurement of distance.
The rangefinder zooms in on the target without affecting the quality of the clarity, and still maintains the accurate distance to the target.
Before we get to how much rangefinders zoom in on the target object, let us take a look at the different ranging capacities of rangefinders.
The different rangefinders we have in existence today have different ranging capacities that are important for their core purposes which could either be golfing, hunting, surveying, shooting, or any other thing you intend to use the rangefinder for.
In this article, I will highlight some types of rangefinders and their ranging capacity.
Ranging Capacities of Some of The Popular Rangefinders
- A ‘Power Disto’ is a laser rangefinder that operates within a range of 1-90 feet;
- ‘Lytespeed 400’ like the name indicates can operate with a range of 400 if the target is a non-reflective target but the ranging capacity increases to about 999-1000 when the target is a reflective object.
- The ‘Ranging 400’ is an optical rangefinder that can operate between the range of 20-400 yards like its name indicates;
- The ‘Laser Atlanta Advantage’ is a laser rangefinder that can operate within 5-32,000 feet if the target is a reflective target.
- The ‘DME 70’ is a ranging device that operates between 10-225 feet;
- An ‘Impulse 200’ has a ranging capacity of a maximum of 1640 feet;
- The ‘Swarovski Optik RF-1’ has a ranging operation between 22-1100 yards.
- The ‘Sonin 60’ is an ultrasonic device that operates within 1-60 feet ranging capacity.
The point of it all is that rangefinders can function within any number of ranging capacities, all you have to do is carry out proper research for the field of range you intend to use the rangefinder for.
How Much Does A Rangefinder Add
Most rangefinders offer a magnification or a zooming feature to enhance the accuracy and clarity of the target. Some rangefinders have up to 4x-more magnification capacity and the magnification capacity of the rangefinder is one of the perks manufacturers use to lure buyers in.
If a magnification feature is important in rangefinders is not in question, what this article hopes to address is how much rangefinders adds to the size of a target.
My answer is simple; it depends on the target and what rangefinder is being used for. Some manufacturers have estimated that when rangefinders are used with shotguns, the targets are magnified by 10%, this also applies to other types of guns.
However, many highly efficient rangefinders have a zooming or a magnifying capacity of about 6x the target size and the return result is a clear and accurate reading.
Every manufactured rangefinder differs from the next, if the magnifying capacity of the rangefinder is really important to you, then it should among your list of questions before you try to purchase one.