Nampa is located at 43°34'29" North, 116°33'49" West (43.574807, -116.563559)^GR1.

According to the United States Census Bureau, the city has a total area of 51.5 km² (19.9 mi²). 51.4 km² (19.9 mi²) of it is land and 0.1 km² (0.04 mi²) of it is water. The total area is 0.10% water.

Zip codes: 83651, 83686, 83687.

Nampa Demographics

As of  2000, there were 51,867 people, 18,090 households, and 13,024 families residing in the city. The population density was 1,008.9/km² (2,612.3/mi²).

There were 18,090 households out of which 40.6% had children under the age of 18 living with them, 55.6% were married couples living together, 11.4% had a female householder with no husband present, and 28.0% were non-families. 22.6% of all households were made up of individuals and 9.6% had someone living alone who was 65 years of age or older. The average household size was 2.77 and the average family size was 3.25.

In the city the population was spread out with 31.0% under the age of 18, 12.5% from 18 to 24, 30.3% from 25 to 44, 15.0% from 45 to 64, and 11.2% who were 65 years of age or older. The median age was 28 years. For every 100 females there were 96.0 males. For every 100 females age 18 and over, there were 93.0 males.

The median income for a household in the city was $34,758, and the median income for a family was $39,434. Males had a median income of $28,580 versus $22,022 for females. The per capita income for the city was $14,491. 12.4% of the population and 8.7% of families were below the poverty line. 13.7% of those under the age of 18 and 9.9% of those 65 and older were living below the poverty line.