Decatur, IL vs O'Fallon, IL

The cost of living difference between Decatur, IL and O'Fallon, IL is dramatic. Decatur is 34.6% cheaper than O'Fallon, a gap that translates to thousands of dollars per year in household expenses. Decatur has a cost index of 62 while O'Fallon sits at 96, making this one of the more striking comparisons on our site. Relocating between these cities would require a serious reassessment of budget and lifestyle expectations.

On the housing front, median rent in Decatur is $796/month compared to $1,312/month in O'Fallon — a 39% difference. Home values follow the same pattern: Decatur is more affordable at $97,300 median vs $274,100.

Median household income in Decatur is $50,809 compared to $102,793 in O'Fallon (-50.6%). While O'Fallon is more expensive, its higher salaries more than compensate — residents there may actually end up with more disposable income. Looking at affordability, residents of Decatur spend roughly 18.8% of their income on rent, more than the 15.3% in O'Fallon.