| Round Rock to Carrollwood (Florida) | 927.92 mi (1,493.35 km) |
| Round Rock to Carson (California) | 1,223.50 mi (1,969.04 km) |
| Round Rock to Carson City (Nevada) | 1,381.92 mi (2,223.99 km) |
| Round Rock to Carteret (New Jersey) | 1,482.82 mi (2,386.36 km) |
| Round Rock to Cartersville (Georgia) | 791.11 mi (1,273.17 km) |
| Round Rock to Carthage (Missouri) | 496.09 mi (798.37 km) |
| Round Rock to Cary (Illinois) | 961.02 mi (1,546.61 km) |
| Round Rock to Cary (North Carolina) | 1,146.71 mi (1,845.46 km) |
| Round Rock to Casa de Oro-Mount Helix (California) | 1,144.34 mi (1,841.63 km) |
| Round Rock to Casa Grande (Arizona) | 844.08 mi (1,358.41 km) |
| Round Rock to Casas Adobes (Arizona) | 796.23 mi (1,281.42 km) |
| Round Rock to Cascades (Virginia) | 1,288.36 mi (2,073.42 km) |
| Round Rock to Casper (Wyoming) | 975.47 mi (1,569.87 km) |
| Round Rock to Casselberry (Florida) | 989.37 mi (1,592.24 km) |
| Round Rock to Castaic (California) | 1,249.49 mi (2,010.85 km) |
