Names and locations in this distance calculator are from the Geographic Names Information System (GNIS), the federal standard for geographic nomenclature, developed for the U.S. Board on Geographic Names (BGN) by the U.S. Geological Survey (USGS), and BGN database of foreign geographic feature names. No attempt has been made to supplement those names with others that may be in common use.

Distance calculations are based on the WGS84 ellipsoid using geod (a part of the PROJ.4 Cartographic Projections library originally written by Gerald Evenden then of the USGS). The computation is for the great circle distance between points, and do not account for differences in elevation.