In comparison, the plasma osmolarity is slightly less than osmolality, because the total plasma weight (the divisor used for osmolality) excludes the weight of any solutes, while the total plasma volume (used for osmolarity) includes solute content.
In comparison, the plasma osmolarity is slightly less than osmolality, although one liter of plasma is equivalent to one kilogram of plasma. This is because the total plasma weight (the divisor used for osmolality) excludes the weight of any solutes, while the total plasma volume (used for osmolarity) includes solute content.