| Portsmouth to Mauldin (South Carolina) | 4,047.19 mi (6,513.32 km) |
| Portsmouth to Maumee (Ohio) | 3,791.66 mi (6,102.09 km) |
| Portsmouth to Maumelle (Arkansas) | 4,454.35 mi (7,168.58 km) |
| Portsmouth to Mayagüez (Puerto Rico) | 4,210.47 mi (6,776.10 km) |
| Portsmouth to Mayfield Heights (Ohio) | 3,705.96 mi (5,964.17 km) |
| Portsmouth to Mays Chapel (Maryland) | 3,601.41 mi (5,795.91 km) |
| Portsmouth to Maywood (California) | 5,443.28 mi (8,760.11 km) |
| Portsmouth to Maywood (Illinois) | 3,941.38 mi (6,343.04 km) |
| Portsmouth to McAlester (Oklahoma) | 4,583.37 mi (7,376.23 km) |
| Portsmouth to McAllen (Texas) | 5,128.61 mi (8,253.69 km) |
| Portsmouth to McCalla (Alabama) | 4,313.23 mi (6,941.47 km) |
| Portsmouth to McComb (Mississippi) | 4,555.59 mi (7,331.51 km) |
| Portsmouth to McDonough (Georgia) | 4,187.69 mi (6,739.44 km) |
| Portsmouth to McFarland (California) | 5,381.66 mi (8,660.95 km) |
| Portsmouth to McHenry (Illinois) | 3,937.81 mi (6,337.29 km) |
