Telescope magnification calculator

Calculate angular magnification with your own figures.

Your numbers

Use the units shown. Results update as you change valid inputs.

Use angular magnification to compare changes to your inputs. The method and limits below explain the scope.

Examples

Examples

Try the starting example

Telescope focal length (mm)
1000
Eyepiece focal length (mm)
20
Barlow/reducer multiplier
1
Angular magnification (×)
50

Try another scenario

Telescope focal length (mm)
1100
Eyepiece focal length (mm)
20
Barlow/reducer multiplier
1
Angular magnification (×)
55
Calculation method

Calculation method

Angular magnification (×)

M=F telescope × multiplier / F eyepiece.

Symbols and units
a
Telescope focal length (mm)
b
Eyepiece focal length (mm)
c
Barlow/reducer multiplier

Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.

Assumptions & limits

Assumptions & limits

  • Calculation uses the entered values and stated mathematical model; quantities must use the labelled units. Supported limits: All required fields must be finite values of the exact declared type and within displayed bounds. Lists contain1–1000 finite numbers. JSON tables are numeric rectangular rows, at most100 rows and30 columns; individual tools have stricter shape/domain constraints. M=F telescope × multiplier / F eyepiece.
Are these inputs private?

These calculations run in your browser. A shared link contains the values you choose to share. Only questions submitted to the separate AI finder are sent to OpenAI.

Further reading

Method reference ↗

Background reading; this does not imply endorsement or independent review of SumFizz.

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