| Middle Valley to Mangualde | 4,099.58 mi (6,597.64 km) |
| Middle Valley to Marco de Canavezes | 4,065.91 mi (6,543.44 km) |
| Middle Valley to Marinha Grande | 4,064.21 mi (6,540.72 km) |
| Middle Valley to Massama | 4,073.09 mi (6,555.00 km) |
| Middle Valley to Matosinhos | 4,039.26 mi (6,500.57 km) |
| Middle Valley to Mealhada | 4,071.67 mi (6,552.72 km) |
| Middle Valley to Melgaco | 4,037.00 mi (6,496.93 km) |
| Middle Valley to Melres | 4,056.74 mi (6,528.69 km) |
| Middle Valley to Mira | 4,056.54 mi (6,528.38 km) |
| Middle Valley to Miranda do Corvo | 4,084.67 mi (6,573.65 km) |
| Middle Valley to Mirandela | 4,104.92 mi (6,606.24 km) |
| Middle Valley to Mogadouro | 4,131.20 mi (6,648.52 km) |
| Middle Valley to Moimenta da Beira | 4,097.06 mi (6,593.58 km) |
| Middle Valley to Moita | 4,090.43 mi (6,582.91 km) |
| Middle Valley to Moncao | 4,027.85 mi (6,482.20 km) |
