| Boulder to Bilecik | 6,222.27 mi (10,013.77 km) |
| Boulder to Bingol | 6,571.17 mi (10,575.28 km) |
| Boulder to Birecik | 6,624.74 mi (10,661.50 km) |
| Boulder to Bitlis | 6,638.35 mi (10,683.39 km) |
| Boulder to Bodrum | 6,325.19 mi (10,179.41 km) |
| Boulder to Bogazliyan | 6,422.43 mi (10,335.91 km) |
| Boulder to Bolu | 6,233.15 mi (10,031.29 km) |
| Boulder to Bolvadin | 6,336.11 mi (10,196.98 km) |
| Boulder to Bor | 6,483.24 mi (10,433.77 km) |
| Boulder to Borcka | 6,442.74 mi (10,368.59 km) |
| Boulder to Boyabat | 6,273.34 mi (10,095.97 km) |
| Boulder to Bozdogan | 6,316.03 mi (10,164.66 km) |
| Boulder to Bozkir | 6,460.16 mi (10,396.62 km) |
| Boulder to Bozkurt | 6,346.91 mi (10,214.36 km) |
| Boulder to Bozuyuk | 6,237.60 mi (10,038.45 km) |
