| Potomac to Maryland Heights (Missouri) | 714.11 mi (1,149.25 km) |
| Potomac to Marysville (California) | 2,356.26 mi (3,792.03 km) |
| Potomac to Marysville (Ohio) | 338.59 mi (544.90 km) |
| Potomac to Marysville (Washington) | 2,301.50 mi (3,703.91 km) |
| Potomac to Maryville (Missouri) | 942.84 mi (1,517.35 km) |
| Potomac to Maryville (Tennessee) | 435.38 mi (700.67 km) |
| Potomac to Mason (Ohio) | 381.30 mi (613.65 km) |
| Potomac to Mason City (Iowa) | 879.49 mi (1,415.41 km) |
| Potomac to Massapequa (New York) | 228.17 mi (367.21 km) |
| Potomac to Massapequa Park (New York) | 229.61 mi (369.52 km) |
| Potomac to Massillon (Ohio) | 260.06 mi (418.53 km) |
| Potomac to Mastic (New York) | 261.58 mi (420.98 km) |
| Potomac to Mastic Beach (New York) | 260.76 mi (419.65 km) |
| Potomac to Matteson (Illinois) | 582.04 mi (936.70 km) |
| Potomac to Matthews (North Carolina) | 331.57 mi (533.61 km) |
