Grantham is located in Sullivan County, New Hampshire. Grantham has a 2025 population of 3,484 . Grantham is currently growing at a rate of 0.03% annually and its population has increased by 2.2% since the most recent census, which recorded a population of 3,409 in 2020.
The average household income in Grantham is $145,971 with a poverty rate of 0%. The median age in Grantham is 51 years: 53.5 years for males, and 50.6 years for females. For every 100 females there are 81.2 males.
Data after 2023 is projected based on recent change
The racial composition of Grantham includes 100% White, and smaller percentages for and multiracial populations.
White (100%)
Race | Population | Percentage (of total) |
|---|---|---|
| White | 3,434 | 100% |
Married
Widowed
Divorced
Separated
Never Married
Grantham's average per capita income is $75,071. Household income levels show a median of $113,510. The poverty rate stands at 0%.
Name | Median | Mean |
|---|---|---|
| Married Families | $159,200 | - |
| Families | $134,833 | $164,026 |
| Households | $113,510 | $145,971 |
| Non Families | $60,818 | $66,531 |
Average Income
Median Household Income
Poverty Rate