| Porsgrunn to Marco de Canavezes | 1,459.51 mi (2,348.86 km) |
| Porsgrunn to Marinha Grande | 1,566.62 mi (2,521.23 km) |
| Porsgrunn to Massama | 1,636.56 mi (2,633.79 km) |
| Porsgrunn to Matosinhos | 1,472.14 mi (2,369.18 km) |
| Porsgrunn to Mealhada | 1,516.14 mi (2,439.99 km) |
| Porsgrunn to Melgaco | 1,404.49 mi (2,260.31 km) |
| Porsgrunn to Melres | 1,472.46 mi (2,369.69 km) |
| Porsgrunn to Mira | 1,519.45 mi (2,445.31 km) |
| Porsgrunn to Miranda do Corvo | 1,531.25 mi (2,464.30 km) |
| Porsgrunn to Mirandela | 1,419.03 mi (2,283.71 km) |
| Porsgrunn to Mogadouro | 1,418.46 mi (2,282.78 km) |
| Porsgrunn to Moimenta da Beira | 1,460.19 mi (2,349.95 km) |
| Porsgrunn to Moita | 1,636.80 mi (2,634.17 km) |
| Porsgrunn to Moncao | 1,412.16 mi (2,272.66 km) |
| Porsgrunn to Montalegre | 1,411.66 mi (2,271.84 km) |
