In the Netherlands, working four days a week is neither a rarity nor a privilege: many people negotiate it with their employer or it’s included in their job offer. You surely know someone who has a vrije dag during the week. But before taking the plunge, the million-dollar question is: how much money do you actually lose when switching from 5 to 4 days? The answer isn’t “just subtract 20% and that’s it”. Let me explain why.

1. How much do you lose in gross terms?

The easy part to calculate. If you work 40 hours and switch to 32 (Monday to Thursday), you’re working 80% of a full-time schedule, so you’ll earn 80% of your salary. With €2,500 gross per month:

• Reduction of 20% (one less day): −€500
• New gross with 4 days: €2,000/month

So far, so clear. But the number that matters isn’t the gross amount, but what actually lands in your bank account after tax.

2. The tax authorities play (a little) in your favour

Income tax in the Netherlands is progressive: the more you earn, the higher the percentage the Belastingdienst takes. And vice-versa: if you earn less, the percentage decreases. That’s why the net loss is smaller than the gross loss. Using the same example of €2,500 gross:

• Current net (40 h): ~€2,314/month
• Net with 4 days (32 h): ~€1,996/month
• Real net loss: ~€318/month, not €462 as it would be if you just subtracted 20% directly

The tax authorities “give back” part of that reduction because you fall into a lower tax bracket. For your exact situation, enter your current gross salary and the new one into the berekenhet.nl calculator.

3. Toeslagen can compensate for some of it

This is what most surprises newcomers: when your salary decreases, you might become eligible for more toeslagen (subsidies), or the ones you already receive might increase. The most common ones are huurtoeslag (rent allowance) and zorgtoeslag (healthcare allowance). If you already receive toeslagen with €2,500 gross and pay €750 in rent, reducing your salary could mean you receive more, and your actual loss would drop from €318 to around €198/month. To see the complete impact —salary + toeslagen + pension all at once— the Nibud tool (werkurenberekenaar) is the most comprehensive.

4. Beware: it’s not all about your monthly salary

Reducing your hours affects other things you might not have had on your radar:

• Pension (pensioen): what you accumulate each month depends on your salary. When it decreases, your contribution to your fund also decreases — and in the long run, this has an impact, especially if you’re over 40. You can view your projections on mijnpensioenoverzicht.nl, and if you want to compensate for it, check out the pension system in the Netherlands.
• Holiday pay (vakantiegeld): that 8% of your annual gross salary that you receive in May also decreases proportionally.
• Holiday days: these are calculated based on your contracted hours, so you’ll have fewer “official” days (although your weekly time off is already greater).
• Bonus or dertiende maand: if your contract includes them, they are calculated based on your reduced salary. Thoroughly review your arbeidscontract before signing the change.

If you want an in-depth analysis of what is truly lost with reduced working hours —pension, mortgage, and career— we break it down in the hidden costs of part-time work.

5. How to know if you can afford it?

The best way to decide this rationally is to create two budgets: one with your 5-day salary and another with your 4-day net salary (plus any new toeslagen, if applicable). The difference will tell you if you can “afford” that fifth day off or if you need to adjust your expenses first. This is something rarely calculated this way in Latin America: here, the system is designed to support lower incomes, so the real loss is often less than it seems. The trick is to do the complete calculations, not just look at the gross amount.

Are you thinking about reducing your working hours, or have you already made the switch and want to know if your numbers add up? Leave your question in the comments.

Working fewer days also changes what you build for retirement. Here is how the Dutch pension system works, so you can check what it means for you.