CPI (Consumer Price Index) — Consumer Price Indicator
What is CPI, how it's calculated and why it's crucial for your finances. Simple guide to the consumer goods and services price index.
What is CPI?
CPI (Consumer Price Index), in Polish wskaźnik cen towarów i usług konsumpcyjnych, is the most popular inflation measure. It measures how prices of goods and services purchased by households change.
When you hear "inflation is 4%", that's CPI — prices from the inflation basket rose on average 4% compared to the previous year.
How is CPI calculated?
- GUS (Polish Central Statistical Office) establishes inflation basket — set of ~1,700 products and services
- Each product is assigned a weight (based on Polish spending patterns)
- Monthly price collection in thousands of sales points
- Calculates weighted average price change
Formula (simplified): CPI = (basket cost in current period / basket cost in base period) × 100
Types of CPI in Poland
- CPI year-on-year (y/y) — comparison with same month last year (most quoted)
- CPI month-on-month (m/m) — change vs. previous month
- Core CPI (bazowy CPI) — excluding food and energy prices (more stable)
Why is CPI important?
- Interest rates — Monetary Policy Council raises/lowers rates in response to CPI
- Indexation — pensions, alimony, rental contracts often indexed to CPI
- Bonds — COI and EDO give coupons linked to CPI inflation
- Salary negotiations — "raise by inflation" means raise by CPI
- Financial planning — real return rate = nominal minus CPI
CPI vs Your personal inflation
CPI is an average. Your personal inflation may be different:
- If you rent (rents rise faster) — your inflation higher
- If you don't have a car (fuel in basket) — your inflation lower
- If you have children (education, clothing) — depends on year
How Freenance Can Help
Freenance tracks your real expenses and lets you compare them with official CPI. You see whether your personal inflation is higher or lower than the national average.
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