Cost of living in Liege (Belgium) is 18% cheaper than in Aalborg (Denmark)
This comparison is lacking data. It provides a decent comparison, but it is not yet reliable. It is based on 127 prices entered by 12 different people.
For example, to keep the same standard of living that would require kr26,000 in Aalborg you would need to make just about kr21,199 (€2,839) in Liege.