Urine osmolality versus specific gravity

Relationship between the specific gravity and osmolality of the urine from normal subjects who have neither glucose nor protein in the urine. For comparison, the relationship between the specific gravity and osmolality for glucose solutions is included. Glucose is larger than the main solutes in normal urine such as sodium, potassium, ammonium, and urea; as a result, a glucose solution has a higher specific gravity at a given osmolality than normal urine.