An electrically-powered device intended to be used by a healthcare professional to manually record and display haematological cell counts of white blood cell populations in a clinical specimen, as observed under a microscope. It typically consists of buttons representing each white blood cell type (e.g., basophil, eosinophil, lymphocyte) which the operator depresses to record an observed cell type, and a screen to display each cell population count. It may also automatically calculate cell population percentages and allow for corrections in case of a miscount.