| Preston to Mangualde | 938.88 mi (1,510.97 km) |
| Preston to Marco de Canavezes | 904.75 mi (1,456.06 km) |
| Preston to Marinha Grande | 1,010.95 mi (1,626.97 km) |
| Preston to Massama | 1,081.96 mi (1,741.25 km) |
| Preston to Matosinhos | 912.17 mi (1,467.99 km) |
| Preston to Mealhada | 962.19 mi (1,548.50 km) |
| Preston to Melgaco | 844.03 mi (1,358.33 km) |
| Preston to Melres | 915.83 mi (1,473.88 km) |
| Preston to Mira | 962.61 mi (1,549.16 km) |
| Preston to Miranda do Corvo | 979.70 mi (1,576.67 km) |
| Preston to Mirandela | 872.90 mi (1,404.80 km) |
| Preston to Mogadouro | 878.38 mi (1,413.61 km) |
| Preston to Moimenta da Beira | 911.87 mi (1,467.51 km) |
| Preston to Moita | 1,085.27 mi (1,746.57 km) |
| Preston to Moncao | 849.92 mi (1,367.82 km) |
