A method for counting blood cells in a sample of whole blood. The method comprises the steps of: (a) providing a sample of whole blood; (b) depositing the sample of whole blood onto a slide, e.g., a microscope slide; (c) employing a spreader to create a blood smear; (d) allowing the blood smear to dry on the slide; (e) measuring absorption or reflectance of light attributable to the hemoglobin in the red blood cells in the blood smear on the slide; (f) recording a magnified two-dimensional digital image of the area of analysis identified by the measurement in step (e) as being of suitable thickness for analysis; and (g) collecting, analyzing, and storing data from the magnified two-dimensional digital image. Optionally, steps of fixing and staining of blood cells on the slide can be employed in the method.