What Does 4-12×50 Mean on a Scope?

Riflescopes are really useful things when you are out hunting or just target practice. The scopes are even used in the actual Military.

The scopes come with different specifications and there are different numbers like 4-12 x 50, 10 x 42, 3-6 x 30, and more. What do these numbers mean?


What is the logic behind the numbering? Well, we are trying to explain that today so, let us start this!

What Does 4-12×50 Mean on a Scope?


The first number that you see on your scope is magnification. Okay, but what is Magnification? It is the measurement of how far you can see in comparison to your naked eyes.

So, a scope with a magnification of 4 can be used to see four times far away. Similarly, a scope with magnification 24 will provide you with magnification that is 24 times more.

So, the first thing that you see in numbers like 10 x 40 and 4-12 x 50 are magnification numbers.

The 10 and 4-12 are magnification ranges but why is there a single number in one and a double number in another? To explain that, we need to understand the types of magnification in riflescopes.

Type of Magnification

There are two types of magnification in any rifle scope, they are:

Fixed Magnification

A fixed magnification scope has a non-adjustable magnification power. This means there is no knob you can turn to get the ideal magnification.

This type of magnification technology is pretty much outdated right now.

It was used in the 60s and 70s and this technology was used back then because it was a really cost-effective way of producing the scopes.

If you have used fixed power scopes, you might agree that these scopes are actually easier to use than the variable ones.

You don’t need to keep tweaking the settings so, you can get nice shots quite easily.

Most of these scopes have a fixed parallax as well. The adjustments were none in these scopes.

These scopes started in the magnification power of 2.5x and it went up to 4x, 6x, and even 8x in some models.

But when adjustable power scopes hit the market and they became more affordable, the fixed power scopes gradually started to become less popular.

Variable Magnification

Variable Powered Scopes are the latest scopes that can be adjusted from one power to the next power, the power level can also be dialed back.

These scopes provide an adjustment ring. The ring is there on the eyepiece and it rotates. They are marked with numbers that tell you what the magnification power is.

Initially, scope manufacturers provided a really low range of magnification but the modern models have really big magnification levels that can go all the way up to 25x.

So, In 4-12 x 50, 4-12x refers to the range of magnification, you can get 4x base magnification with the scope but this can be turned all the way up to 12x. But what this that last number 50? Let us discuss that now!

Size of Objective Lens

An Objective lens is the main part of any scope, binocular, or any other optic device. It is what lets the actual light in.

The size of an objective lens is measured in millimeters and you can see it is marked in the lens or mentioned in the packaging of the scope.

There are a few scopes that don’t tell your their Objective lens size and such products are usually pretty shady.

Anyway, moving on, the size of the objective lens is mentioned in the specification format of the scope.

So, in 4-12 x 50, the last number 50 is the size of the objective lens. We can say that the scope’s objective lens has a size of 50mm. Cool right?

But is that it? Are all Objective lenses 50 mm in size? No, there are multiple size options such as 32mm, 38mm, 40mm, 44mm, and more.

Unlike the magnification level though, objective lens size is not variable.

You cannot change the size of an objective lens yet! So, they are all fixed.

Maybe in the future, we will get the technology that lets us do this. We have to wait for that!

So, What is the meaning of 4-12x 50?

It might be clear now. The meaning of the specification format is quite easy to read.

It is just two things – Magnification and Size of an objective lens.

So, 4-12 x 50 means that the scope has a variable magnification that starts at 4x and goes all the way up to 12x. And the size of the objective lens in the scope is 50mm.

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