Protein-creatinine ratio to estimate protein excretion

This graph illustrates the relation between total 24-hour urinary protein excretion and the total protein-to-creatinine ratio (mg/mg) determined on a random urine specimen. Athough there appears to be a close correlation, there can be wide variability in 24-hour protein excretion at a given total protein-to-creatinine ratio. At a ratio of 4, for example, 24-hour protein excretion varied from 2 to almost 8 g/day/1.73 m².