| Allentown to Popovo | 4,867.59 mi (7,833.63 km) |
| Allentown to Provadia | 4,922.14 mi (7,921.41 km) |
| Allentown to Radnevo | 4,900.25 mi (7,886.19 km) |
| Allentown to Radomir | 4,768.67 mi (7,674.43 km) |
| Allentown to Rakitovo | 4,838.52 mi (7,786.85 km) |
| Allentown to Rakovski | 4,861.65 mi (7,824.08 km) |
| Allentown to Razgrad | 4,871.01 mi (7,839.14 km) |
| Allentown to Razlog | 4,817.39 mi (7,752.84 km) |
| Allentown to Ruse | 4,836.52 mi (7,783.63 km) |
| Allentown to Samokov | 4,802.22 mi (7,728.42 km) |
| Allentown to Sandanski | 4,822.86 mi (7,761.65 km) |
| Allentown to Sevlievo | 4,836.62 mi (7,783.79 km) |
| Allentown to Shumen | 4,898.13 mi (7,882.77 km) |
| Allentown to Silistra | 4,875.28 mi (7,846.00 km) |
| Allentown to Sliven | 4,899.95 mi (7,885.71 km) |
