If you were recruited from abroad to work in the Netherlands with scarce, specific expertise, up to 30% of your gross salary can be paid out tax-free under the 30%-regeling. This page gets you straight to a calculator that applies it - plus what the ruling actually requires.
Instead of your full salary being taxed under Box 1, up to 30% of it is reclassified as a tax-free reimbursement for the extra cost of working abroad. The remaining 70% is taxed normally. It does not reduce your tax rate - it removes a slice of your salary from taxation entirely.
Broadly: you were recruited or transferred from outside the Netherlands, you have expertise that is scarce on the Dutch labor market, and your taxable salary meets a minimum threshold set each year by the Belastingdienst. Your employer applies for the ruling on your behalf, typically within 4 months of your start date to have it backdated.
The ruling runs for a maximum of 5 years from when it starts, and can end earlier if you change employer without a new application, or if your circumstances no longer meet the requirements.
Does the 30% ruling reduce my tax rate?
No - it exempts a portion of your salary from tax entirely, rather than lowering the rate applied to what remains taxable.
Can I apply for it myself?
No, your employer submits the application to the Belastingdienst on your behalf, though you need to meet the eligibility criteria for them to do so.
Does this calculator check my eligibility?
No - the linked calculator applies a simplified 30%-taxable split assuming you already qualify. It does not verify the salary threshold or recruitment criteria; use it once you know you're eligible.