This dataset contains 5 .csv files which were used to compare cell counting methods using the COMET (Counting Method Evaluation Tool). These datasets are described in the manuscript entitled "A Guided Demonstration of the Counting Method Evaluation Tool (COMET) for Implementing the ISO 20391-2 Cell Counting Standard". The datasets can be directly uploaded to the COMET website (https://cell-counting.shinyapps.io/COMET/) and can be used to generate the plots and tables in the manuscript.