| Sonderborg to Smolyan | 1,143.31 mi (1,839.98 km) |
| Sonderborg to Sofia | 1,040.95 mi (1,675.24 km) |
| Sonderborg to Sopot | 1,082.38 mi (1,741.92 km) |
| Sonderborg to Sozopol | 1,182.10 mi (1,902.41 km) |
| Sonderborg to Sredets | 1,170.61 mi (1,883.91 km) |
| Sonderborg to Stamboliyski | 1,106.46 mi (1,780.68 km) |
| Sonderborg to Stara Zagora | 1,120.30 mi (1,802.95 km) |
| Sonderborg to Svilengrad | 1,174.25 mi (1,889.77 km) |
| Sonderborg to Svishtov | 1,044.76 mi (1,681.38 km) |
| Sonderborg to Targovishte | 1,102.06 mi (1,773.59 km) |
| Sonderborg to Teteven | 1,053.53 mi (1,695.50 km) |
| Sonderborg to Troyan | 1,068.01 mi (1,718.79 km) |
| Sonderborg to Tryavna | 1,091.30 mi (1,756.28 km) |
| Sonderborg to Tutrakan | 1,059.57 mi (1,705.22 km) |
| Sonderborg to Varna | 1,145.21 mi (1,843.03 km) |
