| Kalkar to Popovo | 1,090.44 mi (1,754.89 km) |
| Kalkar to Provadia | 1,144.73 mi (1,842.27 km) |
| Kalkar to Radnevo | 1,126.11 mi (1,812.30 km) |
| Kalkar to Radomir | 1,003.82 mi (1,615.49 km) |
| Kalkar to Rakitovo | 1,072.48 mi (1,725.99 km) |
| Kalkar to Rakovski | 1,090.28 mi (1,754.63 km) |
| Kalkar to Razgrad | 1,093.62 mi (1,760.01 km) |
| Kalkar to Razlog | 1,055.20 mi (1,698.19 km) |
| Kalkar to Ruse | 1,059.14 mi (1,704.51 km) |
| Kalkar to Samokov | 1,036.07 mi (1,667.40 km) |
| Kalkar to Sandanski | 1,064.48 mi (1,713.11 km) |
| Kalkar to Sevlievo | 1,061.67 mi (1,708.59 km) |
| Kalkar to Shumen | 1,120.74 mi (1,803.65 km) |
| Kalkar to Silistra | 1,098.80 mi (1,768.35 km) |
| Kalkar to Sliven | 1,123.86 mi (1,808.68 km) |
