| Duffel to Provadia | 1,201.05 mi (1,932.90 km) |
| Duffel to Radnevo | 1,176.58 mi (1,893.52 km) |
| Duffel to Radomir | 1,048.19 mi (1,686.89 km) |
| Duffel to Rakitovo | 1,117.63 mi (1,798.66 km) |
| Duffel to Rakovski | 1,138.59 mi (1,832.38 km) |
| Duffel to Razgrad | 1,149.45 mi (1,849.85 km) |
| Duffel to Razlog | 1,098.44 mi (1,767.77 km) |
| Duffel to Ruse | 1,114.93 mi (1,794.30 km) |
| Duffel to Samokov | 1,081.19 mi (1,740.01 km) |
| Duffel to Sandanski | 1,106.11 mi (1,780.10 km) |
| Duffel to Sevlievo | 1,112.92 mi (1,791.07 km) |
| Duffel to Shumen | 1,176.48 mi (1,893.36 km) |
| Duffel to Silistra | 1,157.92 mi (1,863.49 km) |
| Duffel to Sliven | 1,176.44 mi (1,893.30 km) |
| Duffel to Smolyan | 1,159.74 mi (1,866.43 km) |
