| Birkenhead to Popovo | 1,496.49 mi (2,408.36 km) |
| Birkenhead to Provadia | 1,551.26 mi (2,496.51 km) |
| Birkenhead to Radnevo | 1,530.28 mi (2,462.75 km) |
| Birkenhead to Radomir | 1,403.53 mi (2,258.76 km) |
| Birkenhead to Rakitovo | 1,472.88 mi (2,370.37 km) |
| Birkenhead to Rakovski | 1,493.08 mi (2,402.88 km) |
| Birkenhead to Razgrad | 1,500.01 mi (2,414.04 km) |
| Birkenhead to Razlog | 1,453.92 mi (2,339.86 km) |
| Birkenhead to Ruse | 1,465.51 mi (2,358.51 km) |
| Birkenhead to Samokov | 1,436.43 mi (2,311.71 km) |
| Birkenhead to Sandanski | 1,461.66 mi (2,352.31 km) |
| Birkenhead to Sevlievo | 1,466.24 mi (2,359.68 km) |
| Birkenhead to Shumen | 1,527.12 mi (2,457.66 km) |
| Birkenhead to Silistra | 1,505.68 mi (2,423.16 km) |
| Birkenhead to Sliven | 1,529.12 mi (2,460.87 km) |
