73.208(c) just outlines the mathematical formula used to measure the distance beween two points. REC's database services follow the same formula. Distances are rounded to the nearest kilometer. For example: 4.500 km = 5 km, while 4.499 km = 4 km.
Original Report and Order (01/27/2000) Paras. 58, 68-71
For the purposes of determining compliance with any LPFM distance requirements, distances shall be calculated in accordance with Sec. 73.208(c) of this part.
73.808 Distance computations
For the purposes of determining compliance with any LPFM distance requirements, distances shall be calculated in accordance with Sec. 73.208(c) of this part.
65 FR 7640 (Feb 15, 2000).