Match the payroll situation first
Use the same year and twelve regular payments. Match tax class, registered factor, ZKF, personal allowance, state, church withholding, health additional rate and care facts. Switching annual to monthly entry should preserve the economic salary instead of treating the annual figure as monthly pay. A default fund-specific rate must not be mistaken for a universal statutory rate.
Monthly withholding can differ from the annual reference
For the fictional ordinary class-I case at €5,000 per month and additional health rate 2.9%, monthly wage tax is €782.41. Twelve deductions total €9,388.92, while the annual payroll-period reference is €9,389. The specified discard of fractional cents explains this difference. It is not an extra charge, and neither value is a final tax-return assessment.
Inspect sources before alleging an error
A current year in a title is not evidence of a current algorithm. Compare the final PAP release, source-check dates and insurance rates. In one tested €4,000 scenario another calculator returned €132 less annual wage tax than the official reference under apparently matched facts. The cause remains unresolved. This is not proof that the competitor is outdated; inspect assumptions and rounding before drawing a conclusion.