| Frauenfeld to Smolyan | 877.96 mi (1,412.94 km) |
| Frauenfeld to Sofia | 777.59 mi (1,251.40 km) |
| Frauenfeld to Sopot | 841.90 mi (1,354.91 km) |
| Frauenfeld to Sozopol | 981.77 mi (1,580.01 km) |
| Frauenfeld to Sredets | 961.38 mi (1,547.18 km) |
| Frauenfeld to Stamboliyski | 850.36 mi (1,368.52 km) |
| Frauenfeld to Stara Zagora | 889.21 mi (1,431.04 km) |
| Frauenfeld to Svilengrad | 936.72 mi (1,507.50 km) |
| Frauenfeld to Svishtov | 838.67 mi (1,349.71 km) |
| Frauenfeld to Targovishte | 905.46 mi (1,457.20 km) |
| Frauenfeld to Teteven | 811.55 mi (1,306.06 km) |
| Frauenfeld to Troyan | 832.68 mi (1,340.07 km) |
| Frauenfeld to Tryavna | 868.26 mi (1,397.34 km) |
| Frauenfeld to Tutrakan | 884.78 mi (1,423.92 km) |
| Frauenfeld to Varna | 967.30 mi (1,556.71 km) |
