How Box 3 is calculated

The inputs, formulas, scope and official sources behind this independent Dutch Box 3 calculator.

Two calculations, one comparison

For 2025 and 2026, the calculator estimates Box 3 using deemed returns (forfaitair rendement) and, when your annual information is complete, actual returns (werkelijk rendement). The result is the lower applicable estimate for the supported situation. A difference is a potential reduction in gross Box 3 tax, not a guaranteed refund or your full income-tax assessment.

2025 uses published rates. The 2026 savings and debt rates are provisional, and a forecast requires your expected full-year returns. Individual tax credits, foreign tax credits and income-dependent benefits are outside this estimate.

Assets, debts and cash flows

Enter the relevant 1 January values in EUR. Eligible debts are reduced by the annual debt threshold before the net assets and capital allowance are calculated. Missing values stay unknown; enter zero only when it is actually zero.

For investments and crypto, actual return includes cash income and changes in value. Opening and closing values are reconciled with purchases and sales. Include reinvested dividends in income and the corresponding purchase, so they are counted once. Broker cash and internal transfers must not also be included in the investments total. EUR savings use interest; foreign-currency savings also need their EUR currency gain or loss.

Fiscal partners and expat transition

The mixed-partner mode supports full-year Dutch residents and full-year fiscal partners, one of whom remains eligible for the transitional partial foreign taxpayer election throughout 2025 or 2026. You must confirm the election and allocation of 100% of the joint base to that partner. This mode supports ordinary financial assets only.

The eligibility check requires the expat scheme to have been applied in the final payroll period of 2023 and the transitional entitlement to have continued. A 30% ruling alone is insufficient. The transition ends after 2026. The separate effect of this status is not an actual-return refund.

Property and limits

The ordinary-resident property module covers a simple Dutch second home held for the full year, without sale, qualifying improvements or tenant-protection valuation adjustments. Use the required WOZ valuations and rental income. From 2026, days available for private use are relevant even when you did not physically occupy the home.

Foreign property, assets of minors, migration or a change of tax status during the year, mixed partial status with property, and complex non-Box-3 holdings need a separate calculation. The calculator identifies these limits before presenting a complete result.

Official sources

Rules checked on 8 October 2026