In the Netherlands the tax rate is 36% and then caps out at 52%. There's no scenario in which you will net less than 48% on an increase.
But, if you look at it from a more holistic perspective, there's not just taxes on wages. When you earn little you get rent and healthcare insurance subsidies. You lose these once you earn more, so there are income ranges where extra income leads not only to a tax rate of 36 to 52%, but also a loss of subsidies which can be the equivalent of a tax rate. The marginal net income can therefore be < 30 cents per euro earned.
But that isn't necessarily tax related. Further, there's some non-tax consequences that are left out of the story. (e.g. social housing subsidy is only possible for social homes, which you typically don't want to live in if you don't have to).
I'd be interested how it works in Belgium.