| Potomac to Mattoon (Illinois) | 598.06 mi (962.48 km) |
| Potomac to Mauldin (South Carolina) | 406.29 mi (653.86 km) |
| Potomac to Maumee (Ohio) | 383.80 mi (617.67 km) |
| Potomac to Maumelle (Arkansas) | 886.34 mi (1,426.43 km) |
| Potomac to Mayagüez (Puerto Rico) | 1,559.51 mi (2,509.79 km) |
| Potomac to Mayfield Heights (Ohio) | 283.38 mi (456.05 km) |
| Potomac to Mays Chapel (Maryland) | 41.07 mi (66.09 km) |
| Potomac to Maywood (California) | 2,283.65 mi (3,675.19 km) |
| Potomac to Maywood (Illinois) | 593.46 mi (955.08 km) |
| Potomac to McAlester (Oklahoma) | 1,061.65 mi (1,708.57 km) |
| Potomac to McAllen (Texas) | 1,504.29 mi (2,420.92 km) |
| Potomac to McCalla (Alabama) | 675.21 mi (1,086.65 km) |
| Potomac to McComb (Mississippi) | 920.95 mi (1,482.12 km) |
| Potomac to McDonough (Georgia) | 546.16 mi (878.96 km) |
| Potomac to McFarland (California) | 2,300.55 mi (3,702.37 km) |
