| Birsfelden to Karlovo | 901.72 mi (1,451.19 km) |
| Birsfelden to Karnobat | 1,000.41 mi (1,610.00 km) |
| Birsfelden to Kavarna | 1,039.14 mi (1,672.33 km) |
| Birsfelden to Kazanlak | 929.25 mi (1,495.48 km) |
| Birsfelden to Knezha | 842.57 mi (1,355.99 km) |
| Birsfelden to Kostinbrod | 825.00 mi (1,327.71 km) |
| Birsfelden to Kozloduy | 818.50 mi (1,317.25 km) |
| Birsfelden to Kyustendil | 820.01 mi (1,319.67 km) |
| Birsfelden to Levski | 894.20 mi (1,439.08 km) |
| Birsfelden to Lom | 794.76 mi (1,279.04 km) |
| Birsfelden to Lovech | 882.22 mi (1,419.80 km) |
| Birsfelden to Lukovit | 855.34 mi (1,376.54 km) |
| Birsfelden to Lyaskovets | 928.62 mi (1,494.48 km) |
| Birsfelden to Mezdra | 835.86 mi (1,345.19 km) |
| Birsfelden to Momchilgrad | 966.94 mi (1,556.14 km) |
