| Helensburgh to Smolyan | 1,649.17 mi (2,654.09 km) |
| Helensburgh to Sofia | 1,544.88 mi (2,486.25 km) |
| Helensburgh to Sopot | 1,597.57 mi (2,571.04 km) |
| Helensburgh to Sozopol | 1,715.24 mi (2,760.41 km) |
| Helensburgh to Sredets | 1,700.31 mi (2,736.38 km) |
| Helensburgh to Stamboliyski | 1,615.57 mi (2,600.02 km) |
| Helensburgh to Stara Zagora | 1,640.38 mi (2,639.93 km) |
| Helensburgh to Svilengrad | 1,693.05 mi (2,724.70 km) |
| Helensburgh to Svishtov | 1,572.26 mi (2,530.31 km) |
| Helensburgh to Targovishte | 1,634.54 mi (2,630.54 km) |
| Helensburgh to Teteven | 1,567.24 mi (2,522.24 km) |
| Helensburgh to Troyan | 1,584.92 mi (2,550.68 km) |
| Helensburgh to Tryavna | 1,613.78 mi (2,597.13 km) |
| Helensburgh to Tutrakan | 1,598.12 mi (2,571.92 km) |
| Helensburgh to Varna | 1,684.94 mi (2,711.65 km) |
