| Grays to Mangualde | 844.22 mi (1,358.63 km) |
| Grays to Marco de Canavezes | 816.87 mi (1,314.63 km) |
| Grays to Marinha Grande | 923.91 mi (1,486.89 km) |
| Grays to Massama | 993.78 mi (1,599.34 km) |
| Grays to Matosinhos | 830.00 mi (1,335.76 km) |
| Grays to Mealhada | 873.40 mi (1,405.60 km) |
| Grays to Melgaco | 762.66 mi (1,227.39 km) |
| Grays to Melres | 829.93 mi (1,335.65 km) |
| Grays to Mira | 876.87 mi (1,411.18 km) |
| Grays to Miranda do Corvo | 888.46 mi (1,429.83 km) |
| Grays to Mirandela | 776.30 mi (1,249.33 km) |
| Grays to Mogadouro | 776.14 mi (1,249.07 km) |
| Grays to Moimenta da Beira | 817.42 mi (1,315.51 km) |
| Grays to Moita | 994.03 mi (1,599.74 km) |
| Grays to Moncao | 770.63 mi (1,240.21 km) |
