City comparison
Decatur, IL is about 150 miles (250 km) from Mount Prospect, IL in a straight line. By road, the drive is roughly 200 miles, or about 3 h 15 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 Decatur, IL to Mount Prospect, IL takes about 19 min, covering roughly 150 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.
Decatur has a population of 70,975, vs 56,191 in Mount Prospect — about 1.3× larger by population. By land area, Decatur covers about 44 sq mi vs 11 sq mi for Mount Prospect.
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 | Decatur | Mount Prospect | Difference |
|---|---|---|---|
| Median rent | $770/mo | $1,368/mo | 77.7% higher in Mount Prospect |
| Median home value | $96,800 | $367,900 | 280.1% higher in Mount Prospect |
| Median household income | $49,039 | $100,526 | 105.0% higher in Mount Prospect |
| Groceries index | 93.9 | 106.3 | 13.2% higher in Mount Prospect |
| Utilities index | 91.2 | 84.3 | 8.1% higher in Decatur |
| Transportation index | 99.3 | 100.2 | 0.8% higher in Mount Prospect |
| Healthcare index | 99.5 | 100.4 | 0.8% higher in Mount Prospect |
How much you'd need to earn in the other city to keep the same standard of living.
If you earn $100,000 in Decatur, you'd need $131,391 in Mount Prospect to maintain your standard of living.
Climate, safety, and demographics side by side.
Decatur, IL is about 23.9% cheaper overall than Mount Prospect, IL, based on our cost-of-living index. Housing costs are roughly 97% higher in Mount Prospect than in Decatur. If you earn $80,000 in Decatur, you'd need about $105,113 in Mount Prospect to keep the same standard of living.