| San Juan to McHenry (Illinois) | 2,105.81 mi (3,388.97 km) |
| San Juan to McKeesport (Pennsylvania) | 1,723.39 mi (2,773.52 km) |
| San Juan to McKinleyville (California) | 3,737.91 mi (6,015.59 km) |
| San Juan to McKinney (Texas) | 2,149.32 mi (3,459.00 km) |
| San Juan to McLean (Virginia) | 1,568.73 mi (2,524.63 km) |
| San Juan to McMinnville (Oregon) | 3,735.84 mi (6,012.25 km) |
| San Juan to McMinnville (Tennessee) | 1,696.01 mi (2,729.47 km) |
| San Juan to McNair (Virginia) | 1,574.78 mi (2,534.37 km) |
| San Juan to McPherson (Kansas) | 2,345.52 mi (3,774.75 km) |
| San Juan to Mead Valley (California) | 3,315.24 mi (5,335.36 km) |
| San Juan to Meadow Woods (Florida) | 1,187.34 mi (1,910.84 km) |
| San Juan to Meadowbrook (Virginia) | 1,485.27 mi (2,390.31 km) |
| San Juan to Meadville (Pennsylvania) | 1,808.27 mi (2,910.14 km) |
| San Juan to Mebane (North Carolina) | 1,463.58 mi (2,355.41 km) |
| San Juan to Mechanicsville (Virginia) | 1,493.66 mi (2,403.81 km) |
