Question: is 1 litre equal to 1kg?
Answer: A litre of liquid water has a mass almost exactly equal to one kilogram. ... Because volume changes with temperature and pressure, and pressure uses units of mass, the definition of a kilogram was changed. At standard pressure, one litre of water has a mass of 0.999975 kg at 4 °C, and 0.997 kg at 25 °C.