box 3 calculator

What is Box 3 in the Netherlands?

Box 3 is the Dutch tax category for private wealth. In plain language, it is where your savings, investments, and certain debts are grouped to estimate a taxable return. The government applies deemed return percentages to different asset categories and then taxes that calculated return.

Because the exact percentages and thresholds can change by tax year, a practical calculator should let you adjust assumptions. That is exactly what this tool does: you can enter your own numbers, customize the rates, and quickly estimate the annual tax impact.

How this Box 3 calculator works

1) Add your assets

Enter your bank savings and your investments/other assets separately. This matters because savings often use a different deemed return than stocks, funds, second homes, or other taxable assets.

2) Add your debts

Debts can reduce your taxable wealth, but usually only above a debt threshold. The calculator applies that threshold first, then only the deductible part is used in the tax estimate.

3) Apply allowance and profile

You can choose single taxpayer or fiscal partners. The profile multiplies the allowance and debt threshold by one or two people. Then the calculator determines your taxable Box 3 base.

4) Estimate deemed return and tax

The tool computes a deemed return from the category rates you provide, scales it to your taxable base, and applies the Box 3 tax rate to estimate tax due.

Inputs explained

• Bank savings: checking and savings account balances in Box 3.
• Investments & other assets: portfolio value, crypto, second property equity, etc.
• Debts: liabilities that may be deductible in Box 3.
• Tax-free allowance: exempt wealth per person.
• Debt threshold: minimum debt amount per person before deduction starts.
• Deemed returns: percentages used to estimate annual return by category.
• Tax rate: the rate applied to taxable deemed return.

Practical tips for better planning

• Run at least two scenarios: current year and next year.
• Model year-end cash positions; Box 3 snapshots are date-sensitive.
• Separate low-return cash from higher-risk investments for clearer estimates.
• If you have a partner, test allocation options to reduce combined tax.
• Track legislative updates so your percentages stay current.

Example scenario

Suppose you have €80,000 savings, €120,000 invested assets, and €10,000 debt. With a single taxpayer profile and the default settings in this calculator, the tool estimates your taxable base and tax due in seconds. If your assumptions change (for example a new savings return percentage), update one field and recalculate immediately.

Important note

This is an educational estimator, not tax advice. Box 3 legislation has changed in recent years and may continue to evolve. Always validate your final numbers with official Dutch Tax Administration guidance or a qualified tax adviser.