ACR Calculator
Enter urine albumin and urine creatinine from your lab report. The tool calculates your albumin-to-creatinine ratio in both mg/g and mg/mmol, then gives a quick category.
ACR (mg/g): -
ACR (mg/mmol): -
Category: -
Educational use only. Always discuss test results with your healthcare professional.
What is the albumin creatinine ratio?
The albumin creatinine ratio (ACR) is a urine test used to estimate how much albumin (a protein) is leaking into your urine, adjusted for urine concentration using creatinine. Because urine can be very dilute or very concentrated depending on hydration, using a ratio gives a more reliable result than albumin concentration alone.
ACR is commonly used in chronic kidney disease screening and monitoring, especially for people with diabetes, high blood pressure, cardiovascular disease risk, or known kidney disease.
How this calculator works
This calculator first converts your values into standard units, then applies these formulas:
ACR (mg/mmol) = Albumin (mg/L) ÷ Creatinine (mmol/L)
It reports both unit systems because some labs and guidelines use mg/g, while others use mg/mmol.
ACR categories (general adult reference)
- A1 (normal to mildly increased): less than 30 mg/g (less than 3 mg/mmol)
- A2 (moderately increased): 30 to 300 mg/g (3 to 30 mg/mmol)
- A3 (severely increased): above 300 mg/g (above 30 mg/mmol)
Single values can fluctuate. Clinical interpretation usually depends on repeat testing over time and your overall health context.
Why ACR matters
1) Earlier kidney risk detection
Albumin in urine can rise before estimated glomerular filtration rate (eGFR) drops. That makes ACR useful for catching kidney stress early.
2) Better risk stratification
Higher albuminuria is associated with increased risk for kidney progression and cardiovascular outcomes, even when eGFR seems relatively preserved.
3) Treatment monitoring
Clinicians often track ACR over time to assess response to blood pressure control, glucose management, and kidney-protective therapies.
Example calculation
If your urine albumin is 40 mg/L and urine creatinine is 100 mg/dL:
- Creatinine 100 mg/dL = 1.0 g/L and about 8.84 mmol/L
- ACR (mg/g) = 40 ÷ 1.0 = 40 mg/g
- ACR (mg/mmol) = 40 ÷ 8.84 = 4.52 mg/mmol
This falls in the A2 (moderately increased) range.
Tips for more reliable urine ACR results
- Use a first-morning sample if your clinician recommends it.
- Avoid intense exercise right before testing.
- Tell your clinician if you have fever, infection, menstruation, or dehydration, which can affect values.
- Confirm abnormal results with repeat tests as advised.
Frequently asked questions
Is a high ACR always permanent?
Not always. Temporary increases can happen. Persistent elevation over repeat tests is more meaningful clinically.
Can hydration change ACR?
Hydration changes urine concentration, but the ratio to creatinine helps correct for this effect. Even so, day-to-day variation can still occur.
Do I need both eGFR and ACR?
Usually yes. Kidney health staging typically combines filtration (eGFR) and albuminuria (ACR) for a better picture.
Important note
This albumin creatinine ratio calculator is an educational tool and does not diagnose disease. Always interpret ACR with your clinician, who can account for symptoms, medications, blood pressure, diabetes status, and trends across repeated lab tests.