Methodology
How we calculate real yields, source our data, and ensure transparency.
011. Real Yield Calculation
Real yield represents the actual purchasing power gain (or loss) of an investment after accounting for all costs: fees, taxes, and inflation.
Step 1: Net Yield (after fees)
Subtract annual fees (TER for funds/ETFs, account fees for savings) from the gross yield.
Step 2: After-Tax Yield
Apply the applicable tax rate on interest income. Tax rates vary by country and product type (e.g., Italy taxes government bonds at 12.5% vs 26% for other income).
Step 3: Real Yield (after inflation)
Subtract the current inflation rate (HICP YoY) to determine the change in purchasing power. A positive real yield means your money grows in real terms; negative means it loses purchasing power despite earning interest.
022. Data Sources
European Central Bank (ECB)
- €STR (Euro Short-Term Rate) - official overnight rate
- Government bond yields via SDMX API
Eurostat
- HICP (Harmonised Index of Consumer Prices) - monthly inflation data
- Country-specific inflation rates (Year-over-Year)
Banks & Financial Institutions
- Published interest rates from official bank websites
- Term deposit rates, promotional rates, and conditions
Fund & ETF Providers
- Total Expense Ratios (TER) from official fund documents (KIID/KID)
- Current yields from fund factsheets
3. Tax Rates
Tax rates shown are standard withholding rates for interest income in each country.
- Individual income brackets and total income
- Product type (government bonds may have preferential rates)
- Residency status and double taxation treaties
- Available deductions and exemptions (e.g., German Sparerpauschbetrag)
- Holding period (some jurisdictions offer long-term benefits)
Open Data API
The market data behind this site is available as a free, unauthenticated JSON endpoint. No API key required; CORS is open, so it can be consumed directly from browsers.
GET https://euroyields.com/api/market-data
The response includes the ECB deposit facility and main refinancing rates, Euribor 3M, the euro-area AAA yield curve (1Y/2Y/3Y/10Y), 10-year government bond yields and HICP inflation for 16 countries, plus source attributions and a timestamp. Values refresh from official ECB and Eurostat sources; responses are cached for up to 15 minutes.
A machine-readable feed of headline rate changes (ECB decisions, Euribor and €STR moves) is available at /feed.xml.
If you build on this data, an attribution link to euroyields.com is appreciated. Underlying sources: ECB Data Portal and Eurostat (both free and official).
5. Limitations
Errors are possible
Despite our best efforts, errors may occur. Rates change frequently.
Not Financial Advice
EuroYields is an educational comparison tool only. Nothing on this website constitutes financial, investment, tax, or legal advice. We are not licensed financial advisors.
No Liability
We accept no liability for losses, damages, or missed opportunities resulting from the use or reliance on information provided on this site. Always verify rates and conditions directly with financial institutions before making decisions.
Questions About Our Methodology?
We're happy to explain our approach in more detail or discuss data corrections.
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