| Irmo to Smolyan | 5,411.24 mi (8,708.55 km) |
| Irmo to Sofia | 5,309.46 mi (8,544.74 km) |
| Irmo to Sopot | 5,370.52 mi (8,643.01 km) |
| Irmo to Sozopol | 5,501.08 mi (8,853.13 km) |
| Irmo to Sredets | 5,483.49 mi (8,824.83 km) |
| Irmo to Stamboliyski | 5,382.19 mi (8,661.80 km) |
| Irmo to Stara Zagora | 5,416.46 mi (8,716.94 km) |
| Irmo to Svilengrad | 5,466.41 mi (8,797.34 km) |
| Irmo to Svishtov | 5,356.33 mi (8,620.18 km) |
| Irmo to Targovishte | 5,421.28 mi (8,724.71 km) |
| Irmo to Teteven | 5,339.87 mi (8,593.68 km) |
| Irmo to Troyan | 5,359.80 mi (8,625.77 km) |
| Irmo to Tryavna | 5,392.71 mi (8,678.73 km) |
| Irmo to Tutrakan | 5,389.86 mi (8,674.14 km) |
| Irmo to Varna | 5,476.39 mi (8,813.40 km) |
