According to the United States Census Bureau, the village has a total area of 0.4 square miles (1.1 km²), all of it land.
There were 243 households out of which 31.7% had children under the age of 18 living with them, 55.6% were married couples living together, 10.3% had a female householder with no husband present, and 32.1% were non-families. 30.5% of all households were made up of individuals and 18.9% had someone living alone who was 65 years of age or older. The average household size was 2.35 and the average family size was 2.87.
In the village the population was spread out with 24.7% under the age of 18, 8.2% from 18 to 24, 27.4% from 25 to 44, 24.1% from 45 to 64, and 15.6% who were 65 years of age or older. The median age was 40 years. For every 100 females there were 100.7 males. For every 100 females age 18 and over, there were 94.1 males.
The median income for a household in the village was $38,056, and the median income for a family was $48,021. Males had a median income of $26,583 versus $22,778 for females. The per capita income for the village was $17,684. About 3.6% of families and 3.5% of the population were below the poverty line, including 3.6% of those under age 18 and 2.5% of those age 65 or over.

Irwin Industrial Tools announced in September 2008 that they would be closing the plant at the end of October. Manufacturing of tools are to be moved to China. 
Besides Irwin Industrial, there are a few other business in DeWitt, including two bars, a grocery store and a hair salon.