| Potomac to Smolyan | 5,020.38 mi (8,079.52 km) |
| Potomac to Sofia | 4,918.00 mi (7,914.76 km) |
| Potomac to Sopot | 4,977.99 mi (8,011.30 km) |
| Potomac to Sozopol | 5,106.57 mi (8,218.23 km) |
| Potomac to Sredets | 5,089.46 mi (8,190.69 km) |
| Potomac to Stamboliyski | 4,990.62 mi (8,031.63 km) |
| Potomac to Stara Zagora | 5,023.53 mi (8,084.59 km) |
| Potomac to Svilengrad | 5,074.01 mi (8,165.83 km) |
| Potomac to Svishtov | 4,961.96 mi (7,985.50 km) |
| Potomac to Targovishte | 5,026.50 mi (8,089.37 km) |
| Potomac to Teteven | 4,947.33 mi (7,961.95 km) |
| Potomac to Troyan | 4,966.95 mi (7,993.54 km) |
| Potomac to Tryavna | 4,999.28 mi (8,045.56 km) |
| Potomac to Tutrakan | 4,994.01 mi (8,037.09 km) |
| Potomac to Varna | 5,080.69 mi (8,176.59 km) |
