The general formulation to retrieve the cells density in 1 mL is : number of cells counted/volume in which you measured them.

If you diluted the original culture sample before loading it onto the chamber then multiply the number of cells with the dilution factor:

Number of cells*dilution factor/volume

You will also need to transfer units from mm^3 to mL. So the formulation adds up:

Number of cells*dilution factor/transfer units to volume in mL units.

Finally, if you counted only part of squares, or you counted each of the squares and averaged all the numbers, this will be taken into account in the denominator of the formula:

Number of cells* dilution factor/(units transfer to volume in mL* squares counted).

In the case of Malassez:

Units transfer => 2 mm*2.5mm*0.2 mm = 1 mm^3 == 1 microL . So, if you havent diluted the original sample, and you counted the whole chamber, then you have a density of 100 cells in 1 uL. There are 1,000 uL in 1 mL so you have 100,000 cells/mL.

Thank you very much for your answer !

With regards