 According to the United States Census Bureau, Fieldsboro borough had a total area of 0.269 square miles (0.697 km2), all of which was land.The borough borders Bordentown Township and the Delaware River.The Census Bureau's 2006-2010 American Community Survey showed that (in 2010 inflation-adjusted dollars) median household income was $60,938 (with a margin of error of +/- $19,968) and the median family income was $67,500 (+/- $22,306).