The k-Means cluster analysis is one of the simplest and most common procedures for cluster analysis. Thus, the k-Means method is one of the most widely used methods. It is a partitioning procedure that is particularly suitable for large amounts of data.
The k-means method tries to distribute the data points among the k clusters in such a way that the sum of the distances from each point to the respective cluster centroid is minimised.
And here is the online k-Means Cluster Calculator on DATAtab:
https://datatab.net/statistics-calculator/cluster