Cost of Living Index (COL Index)
A measure of how expensive it is to live in a given city compared to the national average (100), accounting for housing, food, transportation, healthcare, and other essentials.
Cost of Living Index (COL Index) is a term from U.S. wage and occupational data — typically a concept from the BLS Occupational Employment and Wage Statistics survey, the DOL prevailing-wage system, or related employment statistics. The definition here is the practical worker-facing meaning. Understanding Cost of Living Index (COL Index) is part of reading wage data defensibly. BLS and DOL conventions can be subtle — survey methodology, reporting thresholds, geographic definitions, and percentile calculations all shape what the headline numbers actually mean.
Each role-and-city page on SalaryTruth surfaces the Cost of Living Index (COL Index)-relevant values for that specific combination, so the general definition here translates into concrete numbers on the per-role-and-city pages.
How It Works
The cost of living index is essential for comparing salaries across cities. A $100,000 salary in San Francisco (COL ~180) has roughly the same purchasing power as a $56,000 salary in a city with a COL of 100. The index is typically calculated using weighted categories: housing (30-40% of the index, and the biggest driver of variation), food (15%), transportation (10%), healthcare (8%), utilities (8%), and miscellaneous goods and services. CORI (the Council for Community and Economic Research) produces the most widely used COL index, surveying prices in 300+ urban areas quarterly. Key examples: New York City COL ~187 (87% above average), San Francisco ~180, Boston ~152, Austin ~103, Dallas ~96, Memphis ~87. Housing drives the vast majority of variation, grocery and transportation costs differ by 10-20% between cities, while housing costs can differ by 300-400%. SalaryTruth includes COL index data for every city so you can compare real purchasing power, not just nominal salary numbers. A role paying $90,000 in Dallas (COL ~96) often provides a higher standard of living than the same role paying $130,000 in San Francisco (COL ~180).
Related Terms
- Purchasing Power, The real value of your salary after adjusting for local cost of living, what your income can actually buy in terms of housing, food, and services.
- Geographic Pay Differential, The difference in salary for the same job in different cities, reflecting local cost of living, labor supply and demand, state taxes, and industry concentration.
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About This Definition
This definition is part of the SalaryTruth Salary & Career Glossary, 25 terms explaining compensation, salary data, and career development. All salary data from the Bureau of Labor Statistics OEWS survey.