Cell Size Estimation Calculator

Work out cell size estimation instantly with clear inputs, formula shown and shareable results.

About Cell Size Estimation Calculator

Multiplies the graticule divisions spanned by the calibration value for the objective in use to give the specimen size in microns.

Formula

Graticule measurement

Size (microns) = divisions spanned x calibrated microns per division for that objective

Worked example

With the default values below, Cell Size Estimation Calculator returns Measured size of 30.000. Change any input above and every figure here is recalculated in your browser.

Inputs used

Eyepiece graticule divisions spannedaccepts 0.5–200: 12
Calibrated size per divisionaccepts 0.01–100 microns: 2.5 microns
Cells measuredaccepts 1–200: 10

Results

Measured size: 30.000 microns
Measured size: 0.030000 mm
Mean size if the span covered several cells: 3.0000 microns
Cells per millimetre: 33.33

Step by step

1Values used
2Graticule measurement
3Measured size= 30.000 microns
4Measured size= 0.030000 mm
5Mean size if the span covered several cells= 3.0000 microns
6Cells per millimetre= 33.33

Assumptions and limits

The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 6 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is the graticule calibrated?

Against a stage micrometer, separately for each objective, because the calibration changes with magnification.

What sizes are typical?

Bacteria are 1 to 5 microns, animal cells 10 to 30 microns and plant cells often 50 to 100 microns.