City comparison
Castle Rock, CO is about 40 miles (60 km) from Thornton, CO in a straight line. By road, the drive is roughly 50 miles, or about 47 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 Castle Rock, CO to Thornton, CO takes about 5 min, covering roughly 40 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.
Thornton has a population of 141,799, vs 74,065 in Castle Rock — about 1.9× larger by population. By land area, Thornton covers about 37 sq mi vs 35 sq mi for Castle Rock.
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 | Castle Rock | Thornton | Difference |
|---|---|---|---|
| Median rent | $1,810/mo | $1,758/mo | 3.0% higher in Castle Rock |
| Median home value | $577,500 | $445,200 | 29.7% higher in Castle Rock |
| Median household income | $135,985 | $95,064 | 43.0% higher in Castle Rock |
| Groceries index | 101.2 | 101.2 | ≈ equal |
| Utilities index | 91.2 | 91.2 | ≈ equal |
| Transportation index | 99.9 | 99.9 | ≈ equal |
| Healthcare index | 99.9 | 99.9 | ≈ 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 Castle Rock, you'd need $99,874 in Thornton to maintain your standard of living.
Climate, safety, and demographics side by side.
Castle Rock and Thornton have nearly identical overall cost-of-living indices. If you earn $80,000 in Castle Rock, you'd need about $79,899 in Thornton to keep the same standard of living.