| Estoril to Ifield | 967.04 mi (1,556.30 km) |
| Estoril to Ilford | 999.27 mi (1,608.16 km) |
| Estoril to Ilfracombe | 901.05 mi (1,450.10 km) |
| Estoril to Ilkeston | 1,058.25 mi (1,703.09 km) |
| Estoril to Ilkley | 1,110.54 mi (1,787.24 km) |
| Estoril to Immingham | 1,117.76 mi (1,798.86 km) |
| Estoril to Ince-in-Makerfield | 1,074.34 mi (1,728.98 km) |
| Estoril to Inverness | 1,317.99 mi (2,121.11 km) |
| Estoril to Inverurie | 1,322.18 mi (2,127.84 km) |
| Estoril to Ipswich | 1,052.88 mi (1,694.45 km) |
| Estoril to Irlam | 1,070.72 mi (1,723.16 km) |
| Estoril to Irthlingborough | 1,030.89 mi (1,659.06 km) |
| Estoril to Irvine | 1,189.08 mi (1,913.64 km) |
| Estoril to Islington | 994.33 mi (1,600.21 km) |
| Estoril to Iver | 984.28 mi (1,584.05 km) |
