Methodology — Calk24.de | Sources, Formulas and Calculation Basis
How we ensure the quality of our calculators
Calculation Basis
All calculations on Calk24.de are based on currently valid legal regulations, official formulas, and official data sources. The calculators are regularly reviewed and promptly updated when laws change.
Data Sources
- Einkommensteuer / Income Tax: §32a EStG
- Sozialversicherung / Social Insurance: BMAS
- Rentenversicherung / Pension: Deutsche Rentenversicherung
- Unterhalt / Child Support: OLG Düsseldorf
- Energie / Energy: Bundesnetzagentur
- BMI: WHO
Current Data
The calculators use the following current values (as of 2025/2026):
- Basic allowance (Grundfreibetrag): 12,348 EUR
- Contribution assessment limit health/nursing (BBG KV/PV): 69,750 EUR/year
- Contribution assessment limit pension/unemployment (BBG RV/AV): 101,400 EUR/year
- Citizen's allowance (Bürgergeld): 563 EUR/month
- Minimum wage: 13.90 EUR/hour
- Child benefit (Kindergeld): 259 EUR/child
- Pension value: 40.79 EUR (West)
- Mini-job limit: 603 EUR/month
Calculation Methodology
Our tax calculators implement the official tariff formulas of Section 32a EStG with all five tariff zones. Social insurance calculations take into account all contribution assessment limits, the supplementary health insurance contribution, and the care insurance surcharges for childless persons.
Financial calculators use the standard annuity formula for loan calculations and the compound interest formula for savings calculators. For ETF savings plans, partial exemption (30% for equity funds) and the saver's lump sum (1,000 EUR) are taken into account.
Data Privacy in Calculations
All calculations are performed exclusively in the user's browser. No input data is transmitted to our servers or third parties. The calculators work entirely client-side with JavaScript/React.
Disclaimer
Despite careful research and implementation, we cannot guarantee the accuracy of the calculation results. The results are for orientation purposes only and do not replace professional tax, financial, or legal advice. For binding information, please contact a tax advisor, financial advisor, or lawyer.