Box 3 estimator
Enter what you owned on 1 January. You'll see your Box 3 tax, and where each number goes in your return.
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About you
Your Box 3 tax for 2026
€0
Fill in at least one amount to see your estimate.
Not personal tax advice.
Where each number goes in your return
This shows where each amount usually belongs. The field names are guidance, so check them against what you see on your own screen.
Fill in your amounts above and they'll appear here, matched to the fields in your return.
How Box 3 is calculated
Box 3 doesn't tax what your savings and investments actually earned. It taxes a return the government assumes you made. Savings get a low assumed return and investments a higher one, whatever the markets did.
Only the part of your wealth above the tax-free allowance is taxed. The estimator works out what share of your wealth that is, applies the same share to the assumed return, and charges the Box 3 rate on the result. This is the official method, step by step.
The government plans to replace this system with one based on your actual returns. Until that law takes effect, the method above is how Box 3 is calculated. Read the Box 3 guide for the full explanation.
An estimate based on the Belastingdienst's published Box 3 rates and tax-free allowances for 2023 to 2026. Provisional years are marked. The mortgage on the home you live in doesn't count in Box 3. Not personal tax advice: for your own situation, check with the Belastingdienst or a Dutch tax adviser.
Sources
Box 3 rates, Belastingdienst: 2026, 2025, 2024 and 2023 (in Dutch).
Exemptions, Belastingdienst: cash, green investments and insurance in 2026 (in Dutch).
Checked on 13 October 2026.