Weight and volume were defined based on the meter. Volume is just expressed in m³ or litre, which is just 1/1000 of 1 m³. Mass was originally defined such that

Weight and volume were defined based on the meter. Volume is just expressed in m³ or litre, which is just 1/1000 of 1 m³. Mass was originally defined such that 1 kg of water is the mass of one litre of pure water at sea level.