| Redwood City to Popovo | 6,510.62 mi (10,477.82 km) |
| Redwood City to Provadia | 6,545.83 mi (10,534.49 km) |
| Redwood City to Radnevo | 6,570.16 mi (10,573.65 km) |
| Redwood City to Radomir | 6,488.10 mi (10,441.59 km) |
| Redwood City to Rakitovo | 6,549.06 mi (10,539.69 km) |
| Redwood City to Rakovski | 6,549.82 mi (10,540.92 km) |
| Redwood City to Razgrad | 6,504.98 mi (10,468.76 km) |
| Redwood City to Razlog | 6,541.14 mi (10,526.95 km) |
| Redwood City to Ruse | 6,475.08 mi (10,420.63 km) |
| Redwood City to Samokov | 6,515.14 mi (10,485.11 km) |
| Redwood City to Sandanski | 6,556.31 mi (10,551.37 km) |
| Redwood City to Sevlievo | 6,507.08 mi (10,472.13 km) |
| Redwood City to Shumen | 6,529.31 mi (10,507.92 km) |
| Redwood City to Silistra | 6,483.29 mi (10,433.85 km) |
| Redwood City to Sliven | 6,554.61 mi (10,548.63 km) |
