| Helensburgh to Montalegre | 990.21 mi (1,593.59 km) |
| Helensburgh to Montemor-o-Novo | 1,210.57 mi (1,948.22 km) |
| Helensburgh to Montemor-o-Velho | 1,109.73 mi (1,785.94 km) |
| Helensburgh to Montijo | 1,212.85 mi (1,951.89 km) |
| Helensburgh to Mortagua | 1,088.33 mi (1,751.51 km) |
| Helensburgh to Moura | 1,241.97 mi (1,998.76 km) |
| Helensburgh to Murtosa | 1,070.61 mi (1,722.97 km) |
| Helensburgh to Nazare | 1,151.40 mi (1,853.00 km) |
| Helensburgh to Nelas | 1,080.21 mi (1,738.43 km) |
| Helensburgh to Obidos | 1,168.65 mi (1,880.75 km) |
| Helensburgh to Odemira | 1,286.40 mi (2,070.26 km) |
| Helensburgh to Odivelas | 1,207.63 mi (1,943.49 km) |
| Helensburgh to Oeiras | 1,216.02 mi (1,956.99 km) |
| Helensburgh to Olhao | 1,320.08 mi (2,124.47 km) |
| Helensburgh to Oliveira de Azemeis | 1,062.15 mi (1,709.36 km) |
