Having the price per kg or liter on the label is great to compare across the similar products on the same shelf. I do it all the time and in some cases it's the

Having the price per kg or liter on the label is great to compare across the similar products on the same shelf. I do it all the time and in some cases it's the only information I look at. However it's not much useful to combat shrinkflation because if, let's say, icecreams shrink maybe you realize it only when you open the box at home and you get the feeling that something changed. Or if you notice that a pack of food that has always been 500 g is now 450 g. You can't remember with precision the old price per kg but you definitely suspect that the manufacturer is playing the shrinkflation game.