Most GIS applications have this functionality (distance on ellipsoid) built-it. For local distance measuring it is generally better and easier to use a project

Most GIS applications have this functionality (distance on ellipsoid) built-it. For local distance measuring it is generally better and easier to use a projected coordinates system (where units are meters/miles instead of degrees). But if you are using a software without GIS functions (excel?) and only have a dataset with lat/long coordinates, then it is easier to use the short formula ;-)