Urine Albumin/Creatinine Ratio
The albumin/creatinine ratio (ACR) compares the amount of albumin in your urine to the amount of creatinine. Dividing by creatinine corrects for how dilute or concentrated the sample is, so a single random sample can estimate daily albumin loss.
ACR is a cornerstone test for detecting and monitoring early kidney disease, particularly in diabetes and high blood pressure. It's convenient and reliable enough that it often replaces a full 24-hour urine collection.
A higher ACR means more albumin is leaking relative to creatinine, which can signal kidney damage. Values of 30 mg/g or above suggest increased albumin loss, and higher numbers indicate greater leakage. Because it can rise temporarily, an abnormal result is usually confirmed on repeat testing.
A low ACR, under 30 mg/g, is normal and suggests the kidneys are not leaking a concerning amount of albumin.
Under 30 mg/g is normal; 30 to 300 mg/g is moderately increased and above 300 mg/g is severely increased. Your clinician typically confirms an abnormal ACR with two or three samples over time before acting on it.
Sources
- Microalbumin Creatinine Ratio - MedlinePlus
- Urine Albumin-to-Creatinine Ratio (uACR) - National Kidney Foundation
Educational context only, not medical advice or a diagnosis. Reference ranges vary by lab, age and sex; always discuss your results with a clinician.