Albumin Creatinine Ratio Calculator

The ACR test compares the concentration of albumin—a primary blood protein—against creatinine, a waste product filtered out by the kidneys. Because urine concentration fluctuates throughout the day, dividing urinary albumin by urinary creatinine standardizes the measurement. The standard formula used is: acr = (albumin * 1000) / creatinine, where albumin is measured in milligrams per deciliter (mg/dL) or milligrams per liter (mg/L), and creatinine is measured in milligrams per deciliter (mg/dL) or micromoles per liter (depending on the lab's unit scaling).

Imagine a patient receives a urinalysis report showing a urinary albumin concentration of 30 mg/dL and a urinary creatinine concentration of 150 mg/dL. To calculate the ACR, apply the standard formula: acr = (30 * 1000) / 150. First, multiply 30 by 1000 to get 30,000. Next, divide 30,000 by 150. The resulting ACR is 200 mg/g, which places the patient in the moderately increased albuminuria category.

For the most accurate assessment, always use a first-morning urine sample, as it provides the most concentrated and reliable baseline. Avoid vigorous physical exercise for 24 hours prior to testing, as heavy workouts can temporarily elevate urinary protein levels. Additionally, ensure that both albumin and creatinine measurements are derived from the exact same urine specimen to maintain mathematical accuracy.