Sterling is 29 km (18 miles) east of Kenai.
According to the United States Census Bureau, the CDP has a total area of 79.4 square miles (205.6 km²), of which, 77.3 square miles (200.2 km²) of it is land and 2.1 square miles (5.4 km²) of it (2.62%) is water.
There were 1,676 households out of which 40.0% had children under the age of 18 living with them, 66.5% were married couples living together, 6.7% had a female householder with no husband present, and 22.1% were non-families. 17.6% of all households were made up of individuals and 3.4% had someone living alone who was 65 years of age or older. The average household size was 2.80 and the average family size was 3.16.
In the CDP the population was spread out with 30.6% under the age of 18, 6.9% from 18 to 24, 29.0% from 25 to 44, 26.8% from 45 to 64, and 6.7% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 108.4 males. For every 100 females age 18 and over, there were 108.2 males.
The median income for a household in the CDP was $47,700, and the median income for a family was $53,889. Males had a median income of $45,063 versus $27,946 for females. The per capita income for the CDP was $20,741. About 7.7% of families and 10.0% of the population were below the poverty line, including 11.8% of those under age 18 and 5.9% of those age 65 or over.
An archaeological site, containing prehistoric Dena'ina house pits, has been discovered near Sterling, showing that the area was inhabited in prehistoric times.
The main industries around Sterling today are support for tourism and sport fishing and hunting.