| Hartford to Karlovo | 4,676.53 mi (7,526.15 km) |
| Hartford to Karnobat | 4,764.74 mi (7,668.11 km) |
| Hartford to Kavarna | 4,784.08 mi (7,699.23 km) |
| Hartford to Kazanlak | 4,701.69 mi (7,566.64 km) |
| Hartford to Knezha | 4,611.91 mi (7,422.16 km) |
| Hartford to Kostinbrod | 4,604.53 mi (7,410.28 km) |
| Hartford to Kozloduy | 4,586.24 mi (7,380.84 km) |
| Hartford to Kyustendil | 4,604.27 mi (7,409.85 km) |
| Hartford to Levski | 4,659.71 mi (7,499.09 km) |
| Hartford to Lom | 4,564.49 mi (7,345.84 km) |
| Hartford to Lovech | 4,652.54 mi (7,487.55 km) |
| Hartford to Lukovit | 4,627.58 mi (7,447.36 km) |
| Hartford to Lyaskovets | 4,694.26 mi (7,554.67 km) |
| Hartford to Mezdra | 4,610.67 mi (7,420.16 km) |
| Hartford to Momchilgrad | 4,747.85 mi (7,640.92 km) |
