City comparison
O'Fallon, MO is about 30 miles (40 km) from St. Louis, MO in a straight line. By road, the drive is roughly 30 miles, or about 35 min behind the wheel at highway speeds.
Driving distance is a rough estimate (great-circle × 1.25); driving time assumes a 60 mph blended average. Real trips run 10–20% longer with stops.
A direct flight from O'Fallon, MO to St. Louis, MO takes about 3 min, covering roughly 30 miles in a straight line. Connecting itineraries with a layover typically add 1–3 hours.
Block-to-block estimate at ~500 mph cruise, including taxi, climb, and descent — what an airline would publish, not pure airborne time.
St. Louis has a population of 298,018, vs 91,825 in O'Fallon — about 3.2× larger by population. By land area, St. Louis covers about 62 sq mi vs 31 sq mi for O'Fallon.
Population from US Census ACS. Land area from the Census Gazetteer (city proper, excluding inland water).
Cost indices by category, with the US city average (100) marked.
Index: 100 = US city average. Lower is more affordable.
Side-by-side costs, salaries, and sub-category indices.
| Metric | O'Fallon | St. Louis | Difference |
|---|---|---|---|
| Median rent | $1,311/mo | $938/mo | 39.8% higher in O'Fallon |
| Median home value | $283,600 | $174,100 | 62.9% higher in O'Fallon |
| Median household income | $104,863 | $52,941 | 98.1% higher in O'Fallon |
| Groceries index | 99.7 | 99.7 | ≈ equal |
| Utilities index | 71.9 | 71.9 | ≈ equal |
| Transportation index | 98.5 | 98.5 | ≈ equal |
| Healthcare index | 98.7 | 98.7 | ≈ equal |
How much you'd need to earn in the other city to keep the same standard of living.
If you earn $100,000 in O'Fallon, you'd need $98,742 in St. Louis to maintain your standard of living.
Climate, safety, and demographics side by side.
St. Louis, MO is about 1.3% cheaper overall than O'Fallon, MO, based on our cost-of-living index. Housing costs are roughly 3% higher in O'Fallon than in St. Louis. If you earn $80,000 in O'Fallon, you'd need about $78,993 in St. Louis to keep the same standard of living.