The formula
PPP = (net_monthly ÷ col_index) × 100
where net_monthly is the city-currency take-home pay and col_index is the city's cost-of-living index (NYC = 100).
What the number means
A score of 68 means your net salary in that city affords 68% of the lifestyle the same income provides in New York. A score above 100 means more.
< 70
Stretches thin
70 – 110
Roughly parity
> 110
Goes further
Comparison with World Bank PPP
WorthOf PPP
City-level and income-specific. Built from a metro cost basket and your actual net monthly take-home.
World Bank PPP
Country-level and economy-wide. Built from national GDP deflators across all goods and services.
Both are useful — ours answers "how does this offer feel in this city?", theirs answers "how does this economy compare?". Don't mix them in the same sentence.
Limitations
- Inherits every limitation of the underlying COL index (urban bias, sample thinness in small cities).
- Does not adjust for personal consumption patterns — childless renters and families with mortgages see different real PPPs.
- Assumes you actually spend at NYC-equivalent ratios; lifestyle choice can shift the practical figure ±15%.