Makakilo is located at 21°21′10″N 158°5′27″W / 21.35278°N 158.09083°W / 21.35278; -158.09083 (21.352850, -158.090732)[3] on the southern end of the slopes of the Waiʻanae mountain range above the city of Kapolei.

The Interstate H-1 freeway divides more recently developed Kapolei from Makakilo, and traveling eastward on H-1 connects to Waipahu.

The freeway ends about 1.5 miles (2.4 km) west of Makakilo, merging into Farrington Highway (State Rte.

Exit 1 on H-1 is Kalaeloa Road, the entrance to Barbers Point and Campbell Industrial Park.

According to the United States Census Bureau, the CDP has a total area of 3.1 square miles (8.0 km2), all land.