Mortgage Interest Deduction Calculator 2026

Estimate your annual hypotheekrenteaftrek (mortgage interest deduction) for 2026. Enter your mortgage balance, interest rate, and gross income to see the gross deduction, eigenwoningforfait offset, effective Box 1 saving, and net mortgage cost after tax.

How hypotheekrenteaftrek works

In the Netherlands, mortgage interest on your primary residence (eigenwoningschuld) is deductible from your Box 1 taxable income. This reduces the amount of income tax you owe. The deduction is calculated at your marginal tax rate, subject to the afbouw beperking (rate cap) that gradually limits the deductible rate for higher-rate taxpayers.

For 2026, the maximum deductible rate is 37.48% for taxpayers whose marginal rate is 49.50%. This means that if you are in the top bracket, you can only deduct at 37.48% rather than 49.50%. The difference is the afbouw (phaseout) applied since 2020.

Eigenwoningforfait

Alongside the interest deduction, homeowners must add the eigenwoningforfait (notional rental value) to their Box 1 income. For 2026, the eigenwoningforfait is 0.35% of the property's WOZ value for homes below €1.2 million, and 2.35% for the portion above. This notional income is added to your taxable income before applying the mortgage deduction.

Net mortgage cost after tax

The effective after-tax mortgage rate is lower than the nominal rate because of the deduction. For example, a 4.5% mortgage rate at a 37.48% effective deduction rate costs approximately 2.8% net after tax. The calculator shows this net cost so you can compare mortgages on an after-tax basis.

Frequently asked questions

What is hypotheekrenteaftrek?

Hypotheekrenteaftrek is the Dutch mortgage interest deduction. Homeowners can deduct mortgage interest paid on their primary residence from their Box 1 taxable income, reducing the income tax they owe.

What is eigenwoningforfait?

Eigenwoningforfait is a notional rental value that the Belastingdienst adds to your taxable income to represent the benefit of living in your own home. For 2026 it is 0.35% of your home's annual WOZ value for homes below €1.2 million.

Is the mortgage interest deduction being phased out?

The maximum deductible rate is capped and has been reduced each year since 2020. For 2026 the cap is 37.48%. Higher earners cannot deduct at the full 49.50% marginal rate. The deduction itself is not being abolished.

Do interest-only mortgages still qualify?

Mortgages taken out before 2013 that are interest-only (aflossingsvrij) still qualify under transitional rules. Mortgages taken out after 1 January 2013 must be annuity (annuïteit) or linear (lineair) to qualify for the deduction.

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