| Iowa City to Popovo | 5,408.46 mi (8,704.08 km) |
| Iowa City to Provadia | 5,457.49 mi (8,782.99 km) |
| Iowa City to Radnevo | 5,451.70 mi (8,773.66 km) |
| Iowa City to Radomir | 5,334.68 mi (8,585.35 km) |
| Iowa City to Rakitovo | 5,403.06 mi (8,695.39 km) |
| Iowa City to Rakovski | 5,418.70 mi (8,720.55 km) |
| Iowa City to Razgrad | 5,408.70 mi (8,704.46 km) |
| Iowa City to Razlog | 5,386.18 mi (8,668.23 km) |
| Iowa City to Ruse | 5,374.93 mi (8,650.12 km) |
| Iowa City to Samokov | 5,366.71 mi (8,636.89 km) |
| Iowa City to Sandanski | 5,395.30 mi (8,682.90 km) |
| Iowa City to Sevlievo | 5,386.60 mi (8,668.90 km) |
| Iowa City to Shumen | 5,435.54 mi (8,747.66 km) |
| Iowa City to Silistra | 5,403.68 mi (8,696.38 km) |
| Iowa City to Sliven | 5,445.89 mi (8,764.31 km) |
