Tax Class Optimizer

Tax Class Optimizer — Which Steuerklasse Is Best for You?

Compare IV/IV, III/V and IV+Faktor side by side. Includes monthly cash flow, annual tax, and Elterngeld impact if you’re planning a family. Based on official BMF §32a EStG formulas.

Your household details

Tax year

Partner A gross salary (€/year) Higher earner — would be Class III in III/V

Partner B gross salary (€/year) Lower earner — would be Class V in III/V

Federal state (church tax)

Children under 25

Health insurance

Show Elterngeld impact — Are you planning a family or currently pregnant? See how your tax class choice affects parental allowance.

⚠️ Elterngeld planning — enter details

Who will take Elterngeld leave?

Current Steuerklasse of leave-taker

Months before birth / Mutterschutz

Monthly comparison — 2025

RECOMMENDED

IV / IVStandard — equal split

Partner A net/mo—

Partner B net/mo—

Household net/mo—

Annual tax total—

vs IV/IVbaseline

RECOMMENDED

III / VHigher earner advantage

Partner A net/mo—

Partner B net/mo—

Household net/mo—

Annual tax total—

vs IV/IV—

RECOMMENDED

IV+FaktorFairest split~ approximation

Partner A net/mo—

Partner B net/mo—

Household net/mo—

Annual tax total—

vs IV/IV—

Important: Annual tax is the same for all combinations—

III/V monthly cash flow advantage vs IV/IV—

But III/V requires filing a joint tax returnMandatory ⚠️

Elterngeld Impact — Parental Allowance Estimate

Current class Elterngeld/mo

—

based on current Steuerklasse

After switching Elterngeld/mo

—

if switch is made in time

Monthly gain

—

per month of Elterngeld

Total gain over 12 months

—

at standard 12-month leave

⚠️ Elterngeld trap — switching too late

Our recommendation

How do I actually change my Steuerklasse? Step-by-step guide — what form to use, how to apply via ELSTER, and what happens next.

Read the guide →

Switched to III/V? You now must file a joint tax return Wundertax handles it fully in English. Free refund estimate — pay only when you submit.

File with Wundertax →

Note: Tax class combinations (III/V and IV/IV) result in the same total annual tax when filing jointly — the difference is only in monthly cash flow. The IV+Faktor column is an approximation based on the Ehegattensplitting formula — the exact Faktor assigned by your Finanzamt will differ based on individual deductions and allowances. Elterngeld estimates are approximate and based on 65% replacement rate. Individual results may vary. Consult a qualified Steuerberater before making changes that affect Elterngeld. Sources: §32a EStG (BMF Programmablaufplan), §2b BEEG, Familienportal.de.