| Frederick to Smolyan | 5,010.79 mi (8,064.09 km) |
| Frederick to Sofia | 4,908.26 mi (7,899.07 km) |
| Frederick to Sopot | 4,967.92 mi (7,995.10 km) |
| Frederick to Sozopol | 5,095.88 mi (8,201.03 km) |
| Frederick to Sredets | 5,078.92 mi (8,173.74 km) |
| Frederick to Stamboliyski | 4,980.83 mi (8,015.88 km) |
| Frederick to Stara Zagora | 5,013.34 mi (8,068.19 km) |
| Frederick to Svilengrad | 5,063.97 mi (8,149.67 km) |
| Frederick to Svishtov | 4,951.33 mi (7,968.40 km) |
| Frederick to Targovishte | 5,015.74 mi (8,072.05 km) |
| Frederick to Teteven | 4,937.26 mi (7,945.76 km) |
| Frederick to Troyan | 4,956.80 mi (7,977.20 km) |
| Frederick to Tryavna | 4,988.94 mi (8,028.92 km) |
| Frederick to Tutrakan | 4,982.90 mi (8,019.21 km) |
| Frederick to Varna | 5,069.62 mi (8,158.77 km) |
