| Southborough to Carlsbad (New Mexico) | 5,075.32 mi (8,167.94 km) |
| Southborough to Carmel (Indiana) | 4,005.22 mi (6,445.77 km) |
| Southborough to Carmichael (California) | 5,301.16 mi (8,531.40 km) |
| Southborough to Carney (Maryland) | 3,645.18 mi (5,866.35 km) |
| Southborough to Carnot-Moon (Pennsylvania) | 3,745.26 mi (6,027.42 km) |
| Southborough to Carol Stream (Illinois) | 3,991.05 mi (6,422.97 km) |
| Southborough to Carolina (Puerto Rico) | 4,210.92 mi (6,776.81 km) |
| Southborough to Carolina Forest (South Carolina) | 4,003.34 mi (6,442.75 km) |
| Southborough to Carpentersville (Illinois) | 3,987.61 mi (6,417.44 km) |
| Southborough to Carpinteria (California) | 5,489.81 mi (8,834.99 km) |
| Southborough to Carrboro (North Carolina) | 3,908.98 mi (6,290.90 km) |
| Southborough to Carroll (Iowa) | 4,235.24 mi (6,815.95 km) |
| Southborough to Carrollton (Georgia) | 4,267.07 mi (6,867.19 km) |
| Southborough to Carrollton (Texas) | 4,766.96 mi (7,671.68 km) |
| Southborough to Carrollwood (Florida) | 4,432.76 mi (7,133.84 km) |
