Forty Fort is located at 41°16'42" North, 75°52'41" West (41.278611, -75.878333).
According to the United States Census Bureau, the borough has a total area of 1.54 mi2 (3.99 km2). 1.34 mi2 (3.47 km2) of it is land and 0.20 mi2 (0.52 km2) of it is covered by water. The total area is 12.96% water.
Forty Fort is located in the Eastern Standard Time (EST) timezone, GMT-05:00. It observes Daylight Saving Time (DST).