| Rockville Centre to Mangualde | 3,367.67 mi (5,419.74 km) |
| Rockville Centre to Marco de Canavezes | 3,333.53 mi (5,364.80 km) |
| Rockville Centre to Marinha Grande | 3,333.85 mi (5,365.31 km) |
| Rockville Centre to Massama | 3,344.50 mi (5,382.45 km) |
| Rockville Centre to Matosinhos | 3,307.05 mi (5,322.18 km) |
| Rockville Centre to Mealhada | 3,340.26 mi (5,375.63 km) |
| Rockville Centre to Melgaco | 3,303.89 mi (5,317.09 km) |
| Rockville Centre to Melres | 3,324.55 mi (5,350.35 km) |
| Rockville Centre to Mira | 3,325.18 mi (5,351.36 km) |
| Rockville Centre to Miranda do Corvo | 3,353.57 mi (5,397.05 km) |
| Rockville Centre to Mirandela | 3,372.04 mi (5,426.77 km) |
| Rockville Centre to Mogadouro | 3,398.32 mi (5,469.06 km) |
| Rockville Centre to Moimenta da Beira | 3,364.72 mi (5,415.00 km) |
| Rockville Centre to Moita | 3,361.86 mi (5,410.38 km) |
| Rockville Centre to Moncao | 3,294.81 mi (5,302.48 km) |
