Box 3 calculator: your Dutch wealth tax for 2026

How box 3 works in 2026

Box 3 is the Dutch tax on savings and investments, and it surprises almost every international. It does not tax the interest or gains you actually made. It assumes a deemed return on what you owned on 1 January and taxes that deemed return at 36%. The steps, which are exactly what the calculator does:

1. Add up your worldwide savings, investments, crypto, a second home and property abroad at their value on 1 January 2026. Subtract your debts, except the first €3,800 per person, which does not count. Your own home in the Netherlands, its mortgage, pension capital and annuity capital stay out.
2. Take off the tax-free allowance (heffingsvrij vermogen): €59,357 per person, €118,714 for fiscal partners. Below that you pay nothing.
3. Work out the deemed return over your actual mix: 1.28% on bank savings (provisional, the final figure comes early 2027), 6.00% on investments and property, minus 2.70% on the counted debt. Scale it to the part above the allowance.
4. Tax that deemed return at 36%.

Because savings carry a much lower deemed return than investments, the mix matters. €90,000 fully in a savings account gives a tax of about €141. The same €90,000 fully in shares gives about €662.

A home abroad

This is the most common question from expats, and the answer is "yes and no". A home abroad, whether you live in it during holidays, rent it out or leave it empty, counts in box 3 at its market value minus the mortgage on it. It must be declared in your Dutch return and it uses up part of your tax-free allowance.

But if the country has a tax treaty with the Netherlands, and the Netherlands has about 100 of them (Spain, Portugal, Italy, France, Germany, Poland, the UK, the US, India, Turkey, Morocco, Brazil, China and South Africa among them), the treaty gives the right to tax real estate to the country where it stands. The Netherlands then grants relief (aftrek ter voorkoming van dubbele belasting): the Dutch box 3 tax attributable to the property is reduced, usually to zero. The calculator shows this relief as a separate line once you enter a property value and leave the treaty button switched on.

• Rental income from the home is not taxed separately in the Netherlands, because box 3 taxes a deemed return and not the rent. The other country usually does tax the rent, so check its non-resident filing rules.
• Ruling holders whose 30% ruling started before 2024 can still leave foreign assets out of box 3 in 2026. From 2027 everyone reports them.

What is changing

• Counter-evidence. If your actual return (interest, dividends, rent and value changes together, costs not deductible) was lower than the deemed return, you can report the real figure via the Opgaaf werkelijk rendement. The catch: the tax-free allowance then no longer applies, so it only helps when the real return was clearly low.
• A new system from 2028. A law taxing actual returns (Wet werkelijk rendement box 3) is planned to start on 1 January 2028 and was still in the Senate in September 2026.
• Timing matters. Money sitting in a bank on 1 January counts. A large purchase in December or a bonus paid in January changes your base.

Read the full explanation in the guide: Box 3 explained for internationals. If you have a 30% ruling, also see how it interacts with box 3 in the 30% ruling explained.

Questions people ask