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Calculators / Biology / Microscope magnification
Microscope magnification calculator
Calculate total optical magnification and field estimate.
On this page
Total magnification400×
Approximate specimen field diameter0.45mm
Calculator controls
How to calculate
Calculate total optical magnification and field estimate.
total magnification = eyepiece × objective; field diameter ≈ field number ÷ objective
Worked example
Eyepiece magnification: 10; Objective magnification: 40; Eyepiece field number (mm): 18.
Total magnification: 400 ×; Approximate specimen field diameter: 0.45 mm.
Assumptions and limits
Digital zoom, tube factor, camera crop, objective field number compatibility, and calibration can change the observed field.
Results are rounded for display; calculations use unrounded values. Read our calculation methodology.
Understanding the result
Calculate total optical magnification and field estimate. Every assumption remains visible so the result can be checked or changed.
When this tool is useful
Use the microscope magnification for an initial estimate, comparison, or classroom calculation.
Understanding your inputs
| Input | What to enter |
|---|---|
| Eyepiece magnification | Enter a number of at least 0.000001 and no more than 1000000000000. |
| Objective magnification | Enter a number of at least 0.000001 and no more than 1000000000000. |
| Eyepiece field number (mm) | Enter a number of at least 0.000001 and no more than 1000000000000. |
Frequently asked questions
What are the limits of this microscope magnification?
Digital zoom, tube factor, camera crop, objective field number compatibility, and calibration can change the observed field.
Can I use different units?
Use the units printed beside each field. Convert measurements first when your source uses different units.