German Solidarity Surcharge (Solidaritätszuschlag) Calculator
This professional-grade calculator computes Germany’s solidarity surcharge (Soli) across personal income tax, corporate income tax, and capital income withholding. It is designed for taxpayers, finance teams, and advisors who need clear, reliable results with authoritative methodology and full accessibility.
Results
Note: Results are rounded to two decimals for display. Actual assessments may round differently.
Data Source and Methodology
Authoritative Data Source:
1) Solidaritätszuschlaggesetz 1995 (SolzG 1995), as amended by the Abzugsteuerentlastungsmodernisierungsgesetz (2021). Federal Ministry of Justice: https://www.gesetze-im-internet.de/solzg_1995/.
2) Federal Central Tax Office (BZSt): Withholding taxes and surcharge overview: BZSt – Tax withholding amount.
All calculations are strictly based on the formulas and data provided by this source.
The Formula Explained
For single filers:
T_0 = 16{,}956,\quad T_1 = 31{,}527
SolZ(T) = \begin{cases} 0, & T \le T_0 \\ 0.119 \cdot (T - T_0), & T_0 < T \le T_1 \\ 0.055 \cdot T, & T > T_1 \end{cases}
For married/joint assessment:
T_0 = 33{,}912,\quad T_1 = 63{,}055
SolZ(T) = \begin{cases} 0, & T \le T_0 \\ 0.119 \cdot (T - T_0), & T_0 < T \le T_1 \\ 0.055 \cdot T, & T > T_1 \end{cases}
Corporate income tax and capital income withholding:
SolZ = 0.055 \cdot T
Glossary of Variables
-
- Base tax amount (T): The assessed tax before Soli (income tax, corporate tax, or withholding tax).
- SolZ: Solidarity surcharge amount due.
- Filing status: Single or Married/Joint (used only for personal income tax thresholds).
- Taxable amount: Amount to which a flat tax rate applies (for compute mode in corporate/capital scenarios).
- Tax rate (%): Flat tax rate used to derive the base tax for corporate/capital scenarios.
- Effective Soli rate: SolZ divided by T, expressed as a percentage.
How It Works: A Step-by-Step Example
Scenario: Single filer with assessed income tax T = €25,000.
- Thresholds for singles: T0 = €16,956, T1 = €31,527.
- Since €16,956 < €25,000 ≤ €31,527, use the mitigation zone formula.
- Apply SolZ = 0.119 × (T − T0) = 0.119 × (25,000 − 16,956) = 0.119 × 8,044 = €956.236 ≈ €956.24.
- Total tax including Soli = €25,000 + €956.24 = €25,956.24.
- Effective Soli rate on base tax = €956.24 / €25,000 = 3.82%.
Frequently Asked Questions (FAQ)
What is the solidarity surcharge (Soli)?
The Soli is a 5.5% surcharge levied on certain German taxes. Since 2021, most personal income taxpayers no longer pay it due to exemption thresholds and a phase‑in zone.
Who pays Soli on personal income tax?
Only higher-income taxpayers. If your assessed income tax is at or below €16,956 (single) or €33,912 (married), your Soli is €0. Above €31,527 (single) or €63,055 (married), the full 5.5% rate applies. Between these values, a mitigation formula applies.
Does Soli apply to capital income?
Yes. For capital income subject to the 25% withholding (Abgeltungsteuer), Soli is 5.5% of the withholding tax amount.
How is Soli calculated for companies?
Corporations pay Soli at 5.5% of their corporate income tax. Exemption thresholds and the mitigation zone do not apply.
Can I use the compute mode for income tax?
No. German income tax is progressive, so a single flat rate is not appropriate. Please enter your assessed income tax amount from your notice or payroll.
Are child allowances or credits included?
Those should already be reflected in your assessed base tax. This tool applies the statutory Soli formulas to the base tax you provide.
Is this calculator updated for current rules?
Yes. The thresholds and formulas introduced in 2021 remain in force. Should the law change, we will update this tool accordingly.