| Houston to Karlovo | 6,157.28 mi (9,909.19 km) |
| Houston to Karnobat | 6,239.80 mi (10,041.98 km) |
| Houston to Kavarna | 6,251.47 mi (10,060.77 km) |
| Houston to Kazanlak | 6,181.06 mi (9,947.45 km) |
| Houston to Knezha | 6,090.84 mi (9,802.26 km) |
| Houston to Kostinbrod | 6,088.41 mi (9,798.35 km) |
| Houston to Kozloduy | 6,064.80 mi (9,760.36 km) |
| Houston to Kyustendil | 6,091.42 mi (9,803.20 km) |
| Houston to Levski | 6,136.52 mi (9,875.78 km) |
| Houston to Lom | 6,044.10 mi (9,727.04 km) |
| Houston to Lovech | 6,131.44 mi (9,867.60 km) |
| Houston to Lukovit | 6,107.58 mi (9,829.20 km) |
| Houston to Lyaskovets | 6,170.70 mi (9,930.78 km) |
| Houston to Mezdra | 6,092.04 mi (9,804.19 km) |
| Houston to Momchilgrad | 6,231.58 mi (10,028.77 km) |
