| Mercer Island to Mangualde | 5,143.72 mi (8,278.01 km) |
| Mercer Island to Marco de Canavezes | 5,099.96 mi (8,207.60 km) |
| Mercer Island to Marinha Grande | 5,149.43 mi (8,287.21 km) |
| Mercer Island to Massama | 5,190.24 mi (8,352.89 km) |
| Mercer Island to Matosinhos | 5,081.57 mi (8,177.99 km) |
| Mercer Island to Mealhada | 5,132.30 mi (8,259.64 km) |
| Mercer Island to Melgaco | 5,046.70 mi (8,121.88 km) |
| Mercer Island to Melres | 5,097.79 mi (8,204.09 km) |
| Mercer Island to Mira | 5,120.08 mi (8,239.97 km) |
| Mercer Island to Miranda do Corvo | 5,151.27 mi (8,290.18 km) |
| Mercer Island to Mirandela | 5,115.99 mi (8,233.39 km) |
| Mercer Island to Mogadouro | 5,139.39 mi (8,271.04 km) |
| Mercer Island to Moimenta da Beira | 5,128.64 mi (8,253.75 km) |
| Mercer Island to Moita | 5,205.99 mi (8,378.23 km) |
| Mercer Island to Moncao | 5,041.93 mi (8,114.21 km) |
