A $100,000 salary in Austin, Texas and a $100,000 salary in San Francisco are not equal. After accounting for rent, groceries, transportation, and services, the Austin salary has roughly 40–50% more purchasing power.
What Is a Cost-of-Living Index?
A cost-of-living (COL) index measures how expensive a city is relative to a national average (typically indexed at 100). A city with a COL of 120 is 20% more expensive than average; a city at 85 is 15% cheaper.
The most widely used index is the C2ER/ACCRA Cost of Living Index, which surveys prices for housing, groceries, utilities, transportation, healthcare, and miscellaneous goods across hundreds of U.S. cities quarterly.
Key City Comparisons
| City | COL Index | Avg 1BR Rent | Equivalent of $100k |
|---|---|---|---|
| San Francisco, CA | 172 | $2,950 | $58,000 |
| New York City, NY | 163 | $2,700 | $61,000 |
| Seattle, WA | 140 | $2,100 | $71,000 |
| Denver, CO | 120 | $1,750 | $83,000 |
| Chicago, IL | 107 | $1,550 | $93,000 |
| Austin, TX | 103 | $1,450 | $97,000 |
| Atlanta, GA | 96 | $1,350 | $104,000 |
| Phoenix, AZ | 95 | $1,300 | $105,000 |
| Dallas, TX | 95 | $1,350 | $105,000 |
| Oklahoma City, OK | 83 | $900 | $120,000 |
Equivalent purchasing power of $100,000 national-average income.
Housing Is the Biggest Driver
Rent typically accounts for 30–40% of a household budget in expensive cities and 20–25% in affordable ones. The HUD Fair Market Rent data shows that median 1-bedroom rents in San Francisco ($2,950) are more than 3× those in Oklahoma City ($900). This single difference can consume an extra $24,000 per year.
How to Compare Cities Fairly
To find the equivalent salary in a target city, use this formula:
Moving from Austin (COL 103) to San Francisco (COL 172) on $80,000? You'd need $80,000 × (172 ÷ 103) = $133,600 just to maintain the same standard of living.