Question: how heavy is 20 litres of water?
Answer: The density of water is 1 kilogram per liter (kg/L) at 39.2°. This means that 1 liter (L) of water weighs 1 kilogram (kg) and 1 milliliter (mL) of water weighs 1 gram (g). In common US measures, one gallon of water weighs 8.345 pounds.