| Delaware to Smolyan | 5,197.78 mi (8,365.02 km) |
| Delaware to Sofia | 5,094.24 mi (8,198.38 km) |
| Delaware to Sopot | 5,151.16 mi (8,289.99 km) |
| Delaware to Sozopol | 5,273.65 mi (8,487.12 km) |
| Delaware to Sredets | 5,258.00 mi (8,461.93 km) |
| Delaware to Stamboliyski | 5,166.30 mi (8,314.35 km) |
| Delaware to Stara Zagora | 5,195.43 mi (8,361.24 km) |
| Delaware to Svilengrad | 5,247.17 mi (8,444.50 km) |
| Delaware to Svishtov | 5,129.96 mi (8,255.87 km) |
| Delaware to Targovishte | 5,193.04 mi (8,357.40 km) |
| Delaware to Teteven | 5,120.57 mi (8,240.76 km) |
| Delaware to Troyan | 5,139.29 mi (8,270.89 km) |
| Delaware to Tryavna | 5,169.85 mi (8,320.08 km) |
| Delaware to Tutrakan | 5,157.35 mi (8,299.96 km) |
| Delaware to Varna | 5,244.18 mi (8,439.70 km) |
