| South San Francisco to Smolyan | 6,582.64 mi (10,593.73 km) |
| South San Francisco to Sofia | 6,482.50 mi (10,432.57 km) |
| South San Francisco to Sopot | 6,517.24 mi (10,488.48 km) |
| South San Francisco to Sozopol | 6,594.01 mi (10,612.03 km) |
| South San Francisco to Sredets | 6,588.04 mi (10,602.43 km) |
| South San Francisco to Stamboliyski | 6,544.66 mi (10,532.61 km) |
| South San Francisco to Stara Zagora | 6,550.27 mi (10,541.65 km) |
| South San Francisco to Svilengrad | 6,603.90 mi (10,627.94 km) |
| South San Francisco to Svishtov | 6,469.74 mi (10,412.05 km) |
| South San Francisco to Targovishte | 6,518.53 mi (10,490.55 km) |
| South San Francisco to Teteven | 6,490.01 mi (10,444.67 km) |
| South San Francisco to Troyan | 6,501.96 mi (10,463.89 km) |
| South San Francisco to Tryavna | 6,519.89 mi (10,492.75 km) |
| South San Francisco to Tutrakan | 6,468.76 mi (10,410.46 km) |
| South San Francisco to Varna | 6,547.55 mi (10,537.27 km) |
