| Biddeford to Popovo | 4,542.50 mi (7,310.45 km) |
| Biddeford to Provadia | 4,597.13 mi (7,398.36 km) |
| Biddeford to Radnevo | 4,575.03 mi (7,362.80 km) |
| Biddeford to Radomir | 4,443.45 mi (7,151.04 km) |
| Biddeford to Rakitovo | 4,513.30 mi (7,263.45 km) |
| Biddeford to Rakovski | 4,536.42 mi (7,300.66 km) |
| Biddeford to Razgrad | 4,545.97 mi (7,316.04 km) |
| Biddeford to Razlog | 4,492.19 mi (7,229.48 km) |
| Biddeford to Ruse | 4,511.48 mi (7,260.52 km) |
| Biddeford to Samokov | 4,476.99 mi (7,205.02 km) |
| Biddeford to Sandanski | 4,497.70 mi (7,238.35 km) |
| Biddeford to Sevlievo | 4,511.42 mi (7,260.43 km) |
| Biddeford to Shumen | 4,573.09 mi (7,359.67 km) |
| Biddeford to Silistra | 4,550.44 mi (7,323.23 km) |
| Biddeford to Sliven | 4,574.78 mi (7,362.40 km) |
