| Calhoun to Smolyan | 5,547.57 mi (8,927.96 km) |
| Calhoun to Sofia | 5,444.90 mi (8,762.73 km) |
| Calhoun to Sopot | 5,504.23 mi (8,858.21 km) |
| Calhoun to Sozopol | 5,631.35 mi (9,062.78 km) |
| Calhoun to Sredets | 5,614.62 mi (9,035.86 km) |
| Calhoun to Stamboliyski | 5,517.44 mi (8,879.46 km) |
| Calhoun to Stara Zagora | 5,549.50 mi (8,931.05 km) |
| Calhoun to Svilengrad | 5,600.30 mi (9,012.81 km) |
| Calhoun to Svishtov | 5,486.91 mi (8,830.33 km) |
| Calhoun to Targovishte | 5,551.10 mi (8,933.62 km) |
| Calhoun to Teteven | 5,473.57 mi (8,808.87 km) |
| Calhoun to Troyan | 5,493.00 mi (8,840.13 km) |
| Calhoun to Tryavna | 5,524.91 mi (8,891.48 km) |
| Calhoun to Tutrakan | 5,517.69 mi (8,879.86 km) |
| Calhoun to Varna | 5,604.46 mi (9,019.50 km) |
