| Formia to Impruneta | 205.96 mi (331.45 km) |
| Formia to Induno Olona | 396.88 mi (638.72 km) |
| Formia to Inverigo | 379.17 mi (610.21 km) |
| Formia to Inveruno | 378.67 mi (609.42 km) |
| Formia to Inzago | 360.39 mi (579.99 km) |
| Formia to Iseo | 352.06 mi (566.59 km) |
| Formia to Isernia | 39.76 mi (63.98 km) |
| Formia to Isola Capo Rizzuto | 243.31 mi (391.57 km) |
| Formia to Isola del Liri | 28.61 mi (46.04 km) |
| Formia to Isola della Scala | 306.01 mi (492.47 km) |
| Formia to Isola Vicentina | 320.65 mi (516.03 km) |
| Formia to Ispica | 317.33 mi (510.69 km) |
| Formia to Istrana | 314.47 mi (506.10 km) |
| Formia to Itri | 4.48 mi (7.21 km) |
| Formia to Ittiri | 267.55 mi (430.59 km) |
