2020 census

As of the census^[7] of 2020, there were 1,488 people, 697 households, and 429 families living in the town. Peru had 907 housing units. The median age was 49.4.

The racial makeup of the town was 94.4% White, 0.5% Native American, 0.3% Asian, 0.5% from other races, and 4.0% from two or more races. Hispanic or Latino of any race were 0.9% of the population.

There were 624 households, of which 24.3% had children under the age of 18 living with them, 51.1% were married couples living together, 19.3% had a female householder with no husband present, 17.7% had a male householder with no wife present, and 33.7% were non-families. 27.1% of all households were made up of individuals, and 12.6% had someone living alone who was 65 years of age or older. The average household size was 2.44 and the average family size was 3.02.

2010 census

As of the census^[8] of 2010, there were 1,541 people, 629 households, and 446 families living in the town. The population density was 33.0 inhabitants per square mile (12.7/km²). There were 909 housing units at an average density of 19.5 per square mile (7.5/km²). The racial makeup of the town was 97.6% White, 0.6% Native American, 0.3% Asian, 0.3% from other races, and 1.1% from two or more races. Hispanic or Latino of any race were 0.3% of the population.

There were 629 households, of which 28.1% had children under the age of 18 living with them, 57.2% were married couples living together, 7.8% had a female householder with no husband present, 5.9% had a male householder with no wife present, and 29.1% were non-families. 22.3% of all households were made up of individuals, and 12% had someone living alone who was 65 years of age or older. The average household size was 2.45 and the average family size was 2.82.

The median age in the town was 47 years. 18.9% of residents were under the age of 18; 8.3% were between the ages of 18 and 24; 20.4% were from 25 to 44; 36.3% were from 45 to 64; and 16.1% were 65 years of age or older. The gender makeup of the town was 49.5% male and 50.5% female.

2000 census

As of the census^[9] of 2000, there were 1,515 people, 585 households, and 436 families living in the town. The population density was 32.3 inhabitants per square mile (12.5/km²). There were 849 housing units at an average density of 18.1 per square mile (7.0/km²). The racial makeup of the town was 99.27% White, 0.33% Native American, 0.13% Asian, and 0.26% from two or more races. Hispanic or Latino of any race were 0.40% of the population.

There were 585 households, out of which 35.0% had children under the age of 18 living with them, 63.8% were married couples living together, 5.6% had a female householder with no husband present, and 25.3% were non-families. 19.8% of all households were made up of individuals, and 7.9% had someone living alone who was 65 years of age or older. The average household size was 2.59 and the average family size was 2.98.

In the town, the population was spread out, with 26.7% under the age of 18, 5.8% from 18 to 24, 28.2% from 25 to 44, 24.2% from 45 to 64, and 15.1% who were 65 years of age or older. The median age was 40 years. For every 100 females, there were 99.9 males. For every 100 females age 18 and over, there were 99.8 males.

The median income for a household in the town was $38,083, and the median income for a family was $43,047. Males had a median income of $32,171 versus $23,214 for females. The per capita income for the town was $16,383. About 3.4% of families and 6.0% of the population were below the poverty line, including 3.8% of those under age 18 and 7.0% of those age 65 or over.