Telescope Magnification Calculator

Use the free Telescope Magnification Calculator tool to quickly set up your scope for amateur and professional astronomical studies. All you need to do is provide the respective inputs and tap on the calculate button to avail resultant telescopic magnification in a matter of seconds.

Telescopic Magnification Calculator: The next parts will teach you how to determine the magnification of a telescope step by step. It's simple with this Telescope Calculator, which tells you the surface brightness and star magnitude limit in a matter of seconds. This article will teach you about how a telescope works, the telescope magnification equation, and much more. Also, look over the sample questions for a better understanding of the concept.

How to find the Magnification of a Telescope?

The methods of determining a magnification are outlined below. Follow these steps to acquire the results you need in a short amount of time.

  • Evaluate the telescope's objective diameter, f-ratio, and eyepiece local length.
  • Get the image's resolving power and field of vision.
  • Divide the objective's focal length by the eyepiece's focal length to get the image magnification.

For more concepts check out to get quick answers by using this free tool.

Telescope Magnification Equation

A telescope is a device that allows you to see faraway objects. The objective and eyepiece are the two basic components. The objective is simply a mirror or lens in this case, and the eyepiece is a collection of lenses that corrects the beam direction.

The important thing is that the telescope objective receives light from the aperture and processes it through the eyepiece's smaller surface. Because of the quantity of light entering and exiting the telescope is identical, the image is not only magnified but also brightened increases significantly.

The telescope maginification formula is as follows: M = fo/fe


  • fo be the objective focal length
  • fe is eyepiece focal length
  • M is the image maginification

We can say that the magnification of the telescope increases when the focal length of the object increases or when the eyepiece focal length decreases.

Magnification Parameters for Telescopes

The adjustable telescope's specifications are as follows:

  • Do is the objective diameter
  • fr be the f-ration is the ratio of focal length to objective diameter, fr= fo/fe
  • fe is the eyepiece focal length.
  • FOVe stands for field of vision.
  • Pr be the resolving power,Pr =11.58"/Do.
  • FOVs is the scope field of view. FOVs= FOV/M
  • The diameter of the exit pupil is measured by Dep.Dep=Do/M
  • The surface brightness is SB,SB = 2Dep2
  • Lm be the star maginitude limit is Lm = 2 + 5log(Do)
  • Mmin is the minimal magnification.

Telescopic Magnification Examples

Question 1: What is the angular magnification of a telescope with a focal length of 300 cm and a focal length of 3cm?


Consider the problem, we have

The objective lens' focal length=300cm

The eyepiece's focal length=3cm

The magnification of a telescope equation M=fo/fe

M = 300/3

M = 100

As a result,The telescope's angular magnification is 100

FAQs on Telescopic Magnification Calculator

1. How do you figure out how much magnification a telescope has?

Use our free Telescope Magnification calculator to simply calculate the magnification of a telescope. Tap the calculate button after entering the inputs such as the objective's f-ratio diameter, the eyepiece's focal length, resolving power, score field of view, and surface brightness details. Within seconds, you'll have the magnification and star magnitude limit as output.

2. What is the magnification formula?

The ratio of the objective focal length to the focal length of the eyepiece is known as magnification. Telescope Magnificatiom M=fo/fe is the formula.

3. What is the Magnification of a telescope?

Magnification refers the measure of how much the image of an object is magnified by a telescope. Linear magnification and angular magnification are the two types of magnification. Both are used to measure the magnification of optical instruments and are designated by the letter M.

4. What does it imply to have a negative magnification?

The object is inverted when the magnification is negative.