| Harpenden to Idar-Oberstein | 365.01 mi (587.42 km) |
| Harpenden to Idstein | 390.57 mi (628.57 km) |
| Harpenden to Illertissen | 525.20 mi (845.22 km) |
| Harpenden to Illingen | 365.71 mi (588.56 km) |
| Harpenden to Ilmenau | 493.20 mi (793.73 km) |
| Harpenden to Ilsede | 448.42 mi (721.67 km) |
| Harpenden to Ilsenburg | 470.65 mi (757.44 km) |
| Harpenden to Ilsfeld | 463.38 mi (745.74 km) |
| Harpenden to Ilvesheim | 422.71 mi (680.29 km) |
| Harpenden to Immenstadt im Allgau | 555.45 mi (893.91 km) |
| Harpenden to Ingelheim | 387.67 mi (623.89 km) |
| Harpenden to Ingolstadt | 560.29 mi (901.70 km) |
| Harpenden to Iserlohn | 345.28 mi (555.68 km) |
| Harpenden to Isernhagen-Sud | 434.80 mi (699.74 km) |
| Harpenden to Ismaning | 587.72 mi (945.84 km) |
