【How-to】How much does a 10 pound brick weigh underwater

So the density of water is about 12.7% of the density of iron, therefore, it reduces the apparent weight of iron by 12.7%. If it takes, say, 100 newtons of force (about 22.5 pounds) to lift a particular iron weight on land, it would only take 87.3 newtons (19.6 pounds) to lift the same weight in freshwater.