| Hackettstown to Opwijk | 3,676.20 mi (5,916.27 km) |
| Hackettstown to Ostend | 3,618.61 mi (5,823.59 km) |
| Hackettstown to Oud-Heverlee | 3,699.18 mi (5,953.26 km) |
| Hackettstown to Oud-Turnhout | 3,699.22 mi (5,953.32 km) |
| Hackettstown to Oudenaarde | 3,655.62 mi (5,883.14 km) |
| Hackettstown to Oudenburg | 3,622.92 mi (5,830.53 km) |
| Hackettstown to Oupeye | 3,741.87 mi (6,021.96 km) |
| Hackettstown to Overijse | 3,695.11 mi (5,946.71 km) |
| Hackettstown to Overpelt | 3,719.18 mi (5,985.44 km) |
| Hackettstown to Paal | 3,714.11 mi (5,977.29 km) |
| Hackettstown to Peer | 3,722.88 mi (5,991.40 km) |
| Hackettstown to Pepinster | 3,752.71 mi (6,039.41 km) |
| Hackettstown to Peruwelz | 3,663.50 mi (5,895.84 km) |
| Hackettstown to Perwez | 3,710.71 mi (5,971.80 km) |
| Hackettstown to Philippeville | 3,711.24 mi (5,972.66 km) |
