Core inflation vs CPI — what matters more for your finances?

Every month, GUS (Statistics Poland) publishes inflation data, but did you know there are different ways to measure it? Core inflation and CPI (Consumer Price Index) are two key indicators that affect your daily finances in completely different ways.

What is CPI (Consumer Price Index)?

CPI, known in Poland as HICP (Harmonised Index of Consumer Prices), is the official inflation indicator published by GUS. It measures price changes of a basket of 755 goods and services representing the expenses of an average Polish household.

Structure of CPI basket in Poland (2026):

• Food and beverages - 24.5%
• Housing, water, energy - 21.2%
• Transport - 11.8%
• Health - 6.4%
• Clothing and footwear - 4.1%
• Recreation and culture - 7.2%
• Other - 24.8%

Example: If CPI is 5.2%, it means that a basket of goods that cost 1,000 PLN a year ago now costs 1,052 PLN.

What is core inflation?

Core inflation is an indicator that excludes the most volatile components - food and energy prices. NBP (National Bank of Poland) focuses on this indicator because it better reflects long-term price trends.

Why exclude food and energy?

1. Seasonality - vegetable prices fluctuate depending on harvests
2. External factors - oil prices depend on geopolitics
3. Speculation - commodities are vulnerable to speculative investments

Example: In December 2025, CPI inflation was 4.8%, but core inflation only 3.2%. The difference resulted from a 15% increase in gas prices and 8% in food prices.

How to read GUS communications?

Structure of monthly communication:

"In December 2025, prices of consumer goods and services 
increased by 0.3% compared to the previous month 
and by 4.8% compared to the same month 
of the previous year."

What it means:

• 0.3% m/m - monthly growth (month over month)
• 4.8% y/y - annual growth (year over year)

Most important categories to track:

1. Food and non-alcoholic beverages

Why important: They constitute 1/4 of average family expenses.

Impact example: 10% food price increase means an additional 250 PLN monthly for a family spending 2,500 PLN on groceries.

2. Housing, water, gas, energy

Why important: Second largest expense, often fixed.

Example: 20% energy price increase means an additional 100 PLN monthly with a 500 PLN bill.

3. Transport

Why important: Directly affects fuel and transportation costs.

Example: 15% fuel price increase means an additional 150 PLN monthly when spending 1,000 PLN on fuel.

Which indicator is more important for your finances?

CPI - for daily budgeting

When to observe CPI:

• Planning household budget
• Salary increase negotiations
• Decisions about major expenses

Practical example: If CPI grows by 6% annually and your salary by 4%, you're really losing 2% purchasing power. This signals the need to find additional income sources or negotiate a raise.

Core inflation - for long-term decisions

When to observe core inflation:

• Planning long-term investments
• Mortgage decisions
• Savings strategy

Practical example: Core inflation at 3% suggests NBP may keep interest rates at current levels. This is a good time to take a fixed-rate loan.

Impact on NBP interest rates

NBP considers both indicators when making interest rate decisions, but:

When core inflation > CPI:

• NBP may raise rates aggressively
• Signals structural inflation problems
• Your strategy: Consider variable-rate loans

When CPI > core inflation:

• Growth may be temporary
• NBP acts more cautiously
• Your strategy: Invest in assets protecting against food inflation

Example analysis of January 2026 data

GUS data:

• CPI: 5.1% y/y
• Core inflation: 3.8% y/y

CPI breakdown:

• Food: +8.2%
• Energy: +12.1%
• Services: +4.1%
• Durable goods: +2.8%

Analysis for your budget:

Short-term (CPI 5.1%):

• Food budget: +8.2% = additional 205 PLN/month (with 2,500 PLN expenses)
• Energy bills: +12.1% = additional 60 PLN/month (with 500 PLN bill)
• Total impact: about 265 PLN more monthly

Long-term (core inflation 3.8%):

• Deposit interest should be >3.8% to maintain purchasing power
• NBP will likely keep rates at current levels
• Good time to hedge against inflation through ETFs or indexed bonds

How to use this data in practice?

1. Budget planning (CPI)

Monthly expense analysis:

Food (2,500 PLN): 8% increase = +200 PLN
Transport (800 PLN): 6% increase = +48 PLN
Housing (1,200 PLN): 4% increase = +48 PLN
Other (1,500 PLN): 3% increase = +45 PLN
TOTAL: +341 PLN monthly

Action: Increase budget by 340-350 PLN or find savings in other categories.

2. Salary negotiations (CPI)

Argument for raise: "CPI inflation is 5.1%, meaning living costs increased by about 300 PLN monthly. I request a 5.5% raise to maintain real wage value."

3. Long-term investments (core inflation)

Investment profitability threshold: 3.8% + risk margin

Example:

• Government bonds: minimum 4.0%
• Stock ETFs: expected return >6.8%
• Bank deposits: minimum 4.2%

4. Credit decisions

With low core inflation (2-3%):

• Fixed-rate loans
• Longer repayment periods

With high core inflation (>4%):

• Variable-rate loans
• Shorter repayment periods

Tools for tracking inflation

1. Data sources

• GUS - official communications
• NBP - inflation reports
• Trading Economics - international comparisons

2. Mobile apps

Freenance automatically categorizes your expenses and shows how inflation affects your budget in individual categories.

3. Inflation calculators

Real value = Nominal value / (1 + inflation)^years

Example: 10,000 PLN with 4% inflation after 5 years is really 8,219 PLN in today's purchasing power.

Interpretation mistakes

1. Confusing indicators

"Inflation dropped from 5% to 4%" - is this good? Depends on the category. CPI decline with rising core inflation may signal structural problems.

2. Ignoring seasonality

High CPI in winter (energy) and summer (vacations) is normal. Observe annual trends.

3. Overestimating short trends

One month of high inflation is not a trend. Analyze data from last 3-6 months.

Polish market specifics

Banking sector impact:

• Variable rate mortgages: Directly tied to NBP rates, influenced by core inflation
• Deposit rates: Usually follow NBP decisions based on core inflation trends
• Credit availability: Banks tighten lending when core inflation rises rapidly

Regional variations:

• Warsaw: Food and housing costs often exceed national CPI
• Kraków, Wrocław: Similar to Warsaw but with lower housing inflation
• Smaller cities: Usually track national CPI more closely

Government policy responses:

• Fuel subsidies: Can artificially lower CPI while core inflation remains high
• VAT changes: Temporary reductions affect CPI but not long-term trends
• Regulated prices: Energy price caps distort CPI readings

2026 scenarios for Poland

Optimistic scenario:

• CPI: 2.8-3.5%
• Core inflation: 2.5-3.0%
• Your strategy: Bank deposits, stable investments

Base scenario:

• CPI: 4.0-5.5%
• Core inflation: 3.2-4.0%
• Your strategy: Diversification, indexed bonds

Pessimistic scenario:

• CPI: >6%
• Core inflation: >5%
• Your strategy: Real assets, gold, REITs

NBP policy implications

Interest rate decisions:

NBP primarily targets core inflation around 2.5%. Understanding this helps predict:

• Rate hikes: When core inflation consistently >4%
• Rate cuts: When core inflation falls <2%
• Hold decisions: When core inflation is 2-4% and stable

Currency impact:

High core inflation relative to EU average strengthens PLN, affecting:

• Import costs (lower in PLN terms)
• Export competitiveness (reduced)
• Foreign investment attractiveness (higher real yields)

Practical monitoring setup

Weekly routine:

1. Check GUS flash estimates (published around 15th of each month)
2. Compare current data to your personal inflation (tracked in Freenance)
3. Adjust monthly budget if necessary

Monthly analysis:

1. Review detailed GUS breakdown
2. Compare CPI vs core inflation trends
3. Assess impact on investment strategy
4. Review salary negotiation position

Quarterly review:

1. Evaluate portfolio performance vs inflation
2. Rebalance investments if needed
3. Update financial goals based on inflation trends

Integration with financial planning

Emergency fund sizing:

With high CPI, maintain 6-8 months of expenses (instead of standard 3-6) to account for rising costs.

Insurance adjustments:

Review coverage annually - inflation affects replacement costs for property and liability limits.

Retirement planning:

Use core inflation (3-4%) for long-term projections, but stress-test with higher CPI scenarios.

Technology tools for tracking

Automated alerts:

Set up notifications for:

• Monthly GUS releases
• NBP meeting decisions
• Significant category changes (>1% monthly)

Personal inflation calculator:

Track your specific inflation based on actual spending patterns:

Personal inflation = Σ(category weight × category inflation)

Where weights match your actual spending, not national average.

Summary

Both CPI and core inflation matter for your finances, but in different aspects:

CPI - for current budget management and salary negotiations Core inflation - for long-term financial planning and investments

Key principles:

1. Track both indicators regularly
2. Adjust strategy to current situation
3. Don't get surprised by high bills - plan increases in advance
4. Use data for salary negotiation arguments
5. Invest according to core inflation trends
6. Understand Polish market specifics and NBP policy framework

Most important: Inflation isn't an abstract indicator - it's concrete money from your budget. Proper interpretation of GUS data can save you hundreds of PLN monthly.

Understanding the difference between CPI and core inflation gives you a significant advantage in financial planning. Use this knowledge to make informed decisions about investments, loans, and budget management in the Polish market.