| Helston to Mangualde | 667.05 mi (1,073.51 km) |
| Helston to Marco de Canavezes | 631.47 mi (1,016.25 km) |
| Helston to Marinha Grande | 736.99 mi (1,186.07 km) |
| Helston to Massama | 807.95 mi (1,300.28 km) |
| Helston to Matosinhos | 637.79 mi (1,026.43 km) |
| Helston to Mealhada | 688.78 mi (1,108.49 km) |
| Helston to Melgaco | 569.84 mi (917.07 km) |
| Helston to Melres | 642.08 mi (1,033.32 km) |
| Helston to Mira | 688.61 mi (1,108.21 km) |
| Helston to Miranda do Corvo | 706.74 mi (1,137.38 km) |
| Helston to Mirandela | 602.25 mi (969.22 km) |
| Helston to Mogadouro | 609.70 mi (981.21 km) |
| Helston to Moimenta da Beira | 640.19 mi (1,030.28 km) |
| Helston to Moita | 811.82 mi (1,306.50 km) |
| Helston to Moncao | 575.38 mi (925.99 km) |
