| Boston to Karlovo | 1,344.88 mi (2,164.37 km) |
| Boston to Karnobat | 1,430.11 mi (2,301.55 km) |
| Boston to Kavarna | 1,449.59 mi (2,332.89 km) |
| Boston to Kazanlak | 1,369.01 mi (2,203.21 km) |
| Boston to Knezha | 1,278.88 mi (2,058.16 km) |
| Boston to Kostinbrod | 1,276.12 mi (2,053.72 km) |
| Boston to Kozloduy | 1,252.96 mi (2,016.44 km) |
| Boston to Kyustendil | 1,280.78 mi (2,061.21 km) |
| Boston to Levski | 1,325.60 mi (2,133.35 km) |
| Boston to Lom | 1,231.89 mi (1,982.53 km) |
| Boston to Lovech | 1,319.52 mi (2,123.57 km) |
| Boston to Lukovit | 1,295.31 mi (2,084.59 km) |
| Boston to Lyaskovets | 1,360.03 mi (2,188.75 km) |
| Boston to Mezdra | 1,279.53 mi (2,059.21 km) |
| Boston to Momchilgrad | 1,419.17 mi (2,283.93 km) |
