Astronomy & Earth Science
Telescope Magnification Calculator
Lets users compute and verify telescope magnification instantly with formula, steps and examples — no manual math.
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mm
mm
Your result
Magnification
48 ×
Magnification = f_objective / f_eyepiece = 48×.
About this calculator
Telescope magnification = objective focal length ÷ eyepiece focal length. A 1200 mm scope with a 25 mm eyepiece gives 48×. Useful magnification maxes near 2× the aperture in mm.
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