Cost of living in Karlsruhe (Germany) is 26% cheaper than in Amsterdam (Netherlands)
This comparison is lacking data. It provides a decent comparison, but it is not yet reliable. It is based on 1,285 prices entered by 325 different people.
For example, to keep the same standard of living that would require €5,800 in Amsterdam you would need to make just about €4,292 in Karlsruhe.