I recently had a need to calculate distance between a large number of latitude/longitude coordinate pairs. There are many options available if you want to import these in a GIS and run analysis. But there is a simpler and much more accesible way if you aren’t doing very high accuracy calculations.
Here I have a spreadsheet which implements the well-known Haversine formula to calculate distance between 2 coordinates. You can structure your point coordinates into 4 columns Lat1, Lon1, Lat2, Lon2 in decimal degrees and the distance will be calculated in meters.
You can give it a try. Just open this spreadsheet, make a copy it and play with it as you like.
The raw formula is below (Thanks to the reader Samuel who suggested it)
=2 * 6371000 * ASIN(SQRT((SIN((LAT2*(3.14159/180)-LAT1*(3.14159/180))/2))^2+COS(LAT2*(3.14159/180))*COS(LAT1*(3.14159/180))*SIN(((LONG2*(3.14159/180)-LONG1*(3.14159/180))/2))^2))