| Rockford to Popovo | 5,292.91 mi (8,518.12 km) |
| Rockford to Provadia | 5,342.58 mi (8,598.05 km) |
| Rockford to Radnevo | 5,335.11 mi (8,586.04 km) |
| Rockford to Radomir | 5,216.50 mi (8,395.14 km) |
| Rockford to Rakitovo | 5,285.10 mi (8,505.55 km) |
| Rockford to Rakovski | 5,301.51 mi (8,531.95 km) |
| Rockford to Razgrad | 5,293.48 mi (8,519.03 km) |
| Rockford to Razlog | 5,267.78 mi (8,477.67 km) |
| Rockford to Ruse | 5,259.59 mi (8,464.49 km) |
| Rockford to Samokov | 5,248.71 mi (8,446.99 km) |
| Rockford to Sandanski | 5,276.55 mi (8,491.79 km) |
| Rockford to Sevlievo | 5,270.09 mi (8,481.39 km) |
| Rockford to Shumen | 5,320.38 mi (8,562.33 km) |
| Rockford to Silistra | 5,289.42 mi (8,512.50 km) |
| Rockford to Sliven | 5,329.86 mi (8,577.58 km) |
