Romania also don't work like that, in principle. They are simply much poorer country than Norway. 30k EUR salary in Romania is upper middle class income, so it is heavily taxed. People making average wage pay much lower taxes.

Also, if I get the linked calculator right, then it expects you to put MONTHLY salary, in RONs, not EUR. So, just putting 30000 there you get a monthly salary of over 6000 EUR, or 72k per year. And that's taxed at 41%.

Romania is much poorer than Norway, but the tax is the same - it's a flat tax rate. Play with the calculator and you'll see. The numbers are in RON - which is 5 times smaller than the dollar, and the value is implied to be monthly - but it makes no difference because of the flat rate.

In other countries you might have tax brackets, but I know from experience that it's very easy to reach 45% total tax rate (not marginal).

e.g. try Belgium, at 100k the state gets 50% https://www.belgiumtaxcalculator.com/?salary=100000&average=...

Try UK. At 50k you pay "only" 26%, but then in the US you pay almost nothing, if you have a family with kids and use the deductions smartly.

True, Belgium is one of the highest.

> but then in the US you pay almost nothing

Well, not really. In NY that would be 27% (converted). And you pay 31% at $100k in NY (or 34% in 150k ) https://smartasset.com/taxes/new-york-tax-calculator