Telescope Magnification Calculator
Compute telescope magnification M = objective focal length / eyepiece focal length.
Input Data
Objective (primary) focal length in mm.
Eyepiece focal length in mm.
Results
100
Magnification M = f₀/fₑ = 100×.
At a glance:Telescope magnification M = objective focal length f₀ / eyepiece focal length fₑ.
Formula
M = f₀ / fₑ.
How to Use
- Enter objective and eyepiece focal lengths.
- The tool returns magnification M.
Case Studies
f₀=1000, fₑ=10 → 100×
M = 1000/10 = 100×.
FAQ
Higher is better?
Too high lowers brightness and field; limited by aperture and atmosphere.
Max useful?
Rule of thumb ≈ 2× aperture (mm).
Related Tools
References
Content reviewed by the Calculatorism editorial team. Results are for reference only; please refer to the relevant authorities for the official figures.