Box 3 Calculator: calculate your tax for 2026 and 2028
Enter your wealth and instantly see the difference between the current fictitious-return system and the Wet Werkelijk Rendement. Free, no registration.
Use this free Box 3 calculator to calculate your Box 3 tax for both 2026 and 2028. The current system uses fictitious return rates per asset category: 1.37% on savings, 6.00% on other assets. The new system (2028) taxes your actual return, including unrealised capital gains on investments.
Enter your wealth per category, set your expected return, and instantly see the difference in tax burden and net wealth. The calculator accounts for the 2026 tax-free allowance and the 2028 return exemption of €1,800.
How do I read the Box 3 calculation?
The calculator shows your tax under both systems, plus the net difference. A positive difference means you pay more in 2028. At a return below approx. 5.88%, the new system may actually be cheaper than the current fictitious rate.
More Box 3 calculators and context
Indicative calculation based on published legislation. Not tax advice. Consult a tax adviser for your personal situation.