The amount of urinary protein that is excreted in kidney disease is a modifiable risk factor that is closely tied to outcome.1 Protein excretion rate (PER) has been traditionally measured using timed urine collections, typically for a 24-hour period. The PER has long been considered the gold-standard measurement tool for proteinuria, but collecting all of one’s urine over a specified time is cumbersome, and single-specimen untimed albumin-creatinine ratio (ACR) and total urinary protein-creatinine ratio (PCR) have become popular alternatives.