City comparison
Decatur, IL is about 175 miles (275 km) from Rockford, IL in a straight line. By road, the drive is roughly 200 miles, or about 3 h 30 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 Rockford, IL takes about 20 min, covering roughly 175 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.
Rockford has a population of 148,173, vs 70,975 in Decatur — about 2.1× larger by population. By land area, Rockford covers about 65 sq mi vs 44 sq mi for Decatur.
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 | Rockford | Difference |
|---|---|---|---|
| Median rent | $770/mo | $906/mo | 17.7% higher in Rockford |
| Median home value | $96,800 | $114,100 | 17.9% higher in Rockford |
| Median household income | $49,039 | $50,744 | 3.5% higher in Rockford |
| Groceries index | 93.9 | 93.9 | ≈ equal |
| Utilities index | 91.2 | 89.6 | 1.7% higher in Decatur |
| Transportation index | 99.3 | 99.3 | ≈ equal |
| Healthcare index | 99.5 | 99.5 | ≈ 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 Decatur, you'd need $107,044 in Rockford to maintain your standard of living.
Climate, safety, and demographics side by side.
Decatur, IL is about 6.6% cheaper overall than Rockford, IL, based on our cost-of-living index. Housing costs are roughly 24% higher in Rockford than in Decatur. If you earn $80,000 in Decatur, you'd need about $85,635 in Rockford to keep the same standard of living.