Calculators

Microscopy calculators

Quick, sourced calculators for the questions that come up at the microscope and the cell culture bench. Each one shows its formula and a worked example, and runs entirely in your browser.

Choose a calculator Add a scale bar to an image

Calculators

Hemocytometer calculatorCells per mL, viability and the volume to seed, from your chamber counts
Cell seeding calculatorCells per well, suspension and medium volumes for plates, dishes and flasks
Magnification calculatorTotal magnification, and actual size ↔ image size for biology classes
Field of view calculatorFOV diameter from field number, low to high power, camera field, cell size
Resolution and NA calculatorAbbe and Rayleigh limits, confocal and axial resolution, Nyquist pixel size, NA
Pixel size calculatorµm per pixel from camera and objective, from a known distance, or a slide level
Scale bar toolAdd a scale bar to a micrograph in your browser, or work out its length

Which calculator do I need?

Question	Calculator
What magnification am I at?	Magnification calculator
How big is this cell really?	Actual size calculator
How wide is the field I see?	Field of view calculator
What is the smallest detail my objective resolves?	Resolution and NA calculator
Are my camera pixels small enough?	Nyquist pixel size
How many µm is one pixel?	Pixel size calculator
How long should the scale bar be?	Scale bar tool
How many cells per mL did I count?	Hemocytometer calculator
How much suspension goes in each well?	Cell seeding calculator

The formulas at a glance

Quantity	Formula
Total magnification	objective × eyepiece
Actual size	image size ÷ magnification
Field of view diameter	field number ÷ objective
Lateral resolution (Rayleigh)	0.61 × wavelength ÷ NA
Numerical aperture	n × sin(half-angle)
Pixel size at the sample	camera pixel × binning ÷ (objective × adapter)
Scale bar length	bar length (µm) ÷ pixel size (µm/px)
Hemocytometer (Neubauer)	cells per large square × 10⁴ × dilution = cells/mL
Cells per well	density (cells/cm²) × growth area

Questions

Are these microscopy calculators free?

Yes. They run in your browser and send nothing anywhere; the scale bar tool draws on your image inside the page without uploading it. SlideScope, the desktop microscopy app made by the same team, is a paid app with a free preview.

How do I calculate total magnification?

Objective magnification × eyepiece magnification: a 40× objective with a 10× eyepiece gives 400×.

How do I calculate the field of view?

Divide the eyepiece field number (mm) by the objective magnification: 22 ÷ 40 = 0.55 mm.

How do I calculate microns per pixel?

Camera pixel size × binning ÷ (objective × camera adapter): 6.5 µm ÷ 20 = 0.325 µm per pixel.

How do I calculate cells per mL from a hemocytometer?

Average cells per large square × 10⁴ × dilution factor, for an improved Neubauer chamber.

Measure on your real images

SlideScope opens 34 microscope and slide-scanner formats, CZI, ND2, SVS and LIF among them, with their own calibration, so lengths, areas, cell counts and scale bars come out in µm without setting anything up. Open a few of your own images with the free preview. Already decided? Subscribe now.

Download SlideScope