| Oak Ridge to Popovo | 5,434.37 mi (8,745.78 km) |
| Oak Ridge to Provadia | 5,488.16 mi (8,832.34 km) |
| Oak Ridge to Radnevo | 5,468.62 mi (8,800.90 km) |
| Oak Ridge to Radomir | 5,338.75 mi (8,591.89 km) |
| Oak Ridge to Rakitovo | 5,408.52 mi (8,704.17 km) |
| Oak Ridge to Rakovski | 5,430.73 mi (8,739.91 km) |
| Oak Ridge to Razgrad | 5,437.31 mi (8,750.50 km) |
| Oak Ridge to Razlog | 5,387.87 mi (8,670.94 km) |
| Oak Ridge to Ruse | 5,402.86 mi (8,695.07 km) |
| Oak Ridge to Samokov | 5,372.16 mi (8,645.65 km) |
| Oak Ridge to Sandanski | 5,393.77 mi (8,680.43 km) |
| Oak Ridge to Sevlievo | 5,404.68 mi (8,698.00 km) |
| Oak Ridge to Shumen | 5,464.43 mi (8,794.15 km) |
| Oak Ridge to Silistra | 5,440.08 mi (8,754.97 km) |
| Oak Ridge to Sliven | 5,467.54 mi (8,799.16 km) |
