| San Marcos to Petaluma (California) | 466.86 mi (751.34 km) |
| San Marcos to Petersburg (Virginia) | 2,247.98 mi (3,617.78 km) |
| San Marcos to Pflugerville (Texas) | 1,162.51 mi (1,870.88 km) |
| San Marcos to Pharr (Texas) | 1,234.89 mi (1,987.36 km) |
| San Marcos to Phelan (California) | 92.37 mi (148.66 km) |
| San Marcos to Phenix City (Alabama) | 1,860.42 mi (2,994.06 km) |
| San Marcos to Philadelphia (Pennsylvania) | 2,358.17 mi (3,795.11 km) |
| San Marcos to Phillipsburg (New Jersey) | 2,354.48 mi (3,789.16 km) |
| San Marcos to Phoenix (Arizona) | 295.00 mi (474.75 km) |
| San Marcos to Phoenixville (Pennsylvania) | 2,337.50 mi (3,761.84 km) |
| San Marcos to Picayune (Mississippi) | 1,619.71 mi (2,606.67 km) |
| San Marcos to Pickerington (Ohio) | 1,953.88 mi (3,144.47 km) |
| San Marcos to Pico Rivera (California) | 79.14 mi (127.36 km) |
| San Marcos to Piedmont (California) | 430.91 mi (693.48 km) |
| San Marcos to Pierre (South Dakota) | 1,190.64 mi (1,916.15 km) |
