Health calculators

Albumin Creatinine Ratio Calculator

Updated Oct 7, 2026 By Infinity Calculator
Rate Formulas Sources Medical disclaimer

Urine Sample Values

Enter the concentration of albumin found in the urine sample.
 
Enter the concentration of creatinine found in the urine sample.
 
Is the patient a Type I diabetic? (required)

Result

Albumin-to-Creatinine Ratio
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Traditional Terminology
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Step-by-Step Solution

Your ACR vs. Category Cut-offs

 

KDIGO Albuminuria Categories — Your Result Highlighted

The row matching your calculated ACR is marked with "Your result".
ACR (mg/g) ACR (mg/mmol) Category Short Label Traditional Term Match

Introduction

The Albumin Creatinine Ratio Calculator (ACR calculator) tells you how much albumin is in your urine compared to creatinine. Albumin is a protein. Healthy kidneys keep it in your blood. When kidneys are damaged, albumin leaks into the urine. Comparing it to creatinine corrects for how watery or strong the urine sample is, so the result works with a single random sample instead of a full 24-hour collection.2

Enter your urine albumin and urine creatinine from your lab report, pick the right units, and say whether you have Type 1 diabetes. You get your ACR in both mg/g and mg/mmol, along with your KDIGO category:

  • A1: under 30 mg/g (normal to mildly increased, or normoalbuminuria)
  • A2: 30 to 299 mg/g (moderately increased, or microalbuminuria)
  • A3: 300 mg/g or more (severely increased, or macroalbuminuria)1

A step-by-step solution, a chart, and a reference table show you how the number was worked out and what it means. This is a screening tool for chronic kidney disease and is often used with an eGFR test. One high result does not confirm kidney disease. A raised result has to last at least 3 months to count as chronic kidney disease, so doctors repeat the test.1 Always talk to your doctor about your results.

How to use our Albumin Creatinine Ratio Calculator

Enter your urine albumin level, your urine creatinine level, and whether you have Type I diabetes. The calculator gives you your albumin-to-creatinine ratio (ACR) in mg/g and mg/mmol, your KDIGO category (A1, A2, or A3), and a step-by-step look at the math.

Urine Albumin: Type the albumin number from your urine test. Then pick the unit that matches your lab report: mg/dL or mg/L.

Urine Creatinine: Type the creatinine number from the same urine sample. Then pick the matching unit: mg/dL, g/dL, or µmol/L.

Is the patient a Type I diabetic? Choose Yes or No. This changes how the result is labeled, since albumin in urine is an early sign of kidney damage in people with Type I diabetes.3

Calculate: Click Calculate to see your ACR, your albuminuria category, a severity scale, and a chart that compares your result to the 30 mg/g and 300 mg/g cut-offs. Click Reset to clear the form and start over.

What Is the Albumin-to-Creatinine Ratio (ACR)?

The albumin-to-creatinine ratio, or ACR, is a urine test that checks how much albumin leaks into your pee. Albumin is a protein your blood needs. Healthy kidneys keep it in the blood. Damaged kidneys let it slip out. So albumin in urine is an early warning sign of kidney damage.3

Why Creatinine Is Part of the Test

Urine can be watery or strong, depending on how much you drink. That changes how much albumin shows up in one sample. Creatinine is a waste product your body makes at a steady rate. By dividing albumin by creatinine, the test cancels out how watered-down the sample is. That is why the ratio is more reliable than albumin alone, and why a random "spot" urine sample works instead of a full 24-hour collection.2

How ACR Is Reported

ACR is usually given in milligrams of albumin per gram of creatinine (mg/g). Many labs outside the U.S. use mg/mmol instead. To switch between them, divide mg/g by 8.84 to get mg/mmol.

ACR Levels and What They Mean

Kidney doctors use the KDIGO system to sort results into three groups:

  • A1, under 30 mg/g: normal to mildly increased. Older term: normoalbuminuria.
  • A2, 30 to 299 mg/g: moderately increased. Older term: microalbuminuria.
  • A3, 300 mg/g or more: severely increased.1 Older term: macroalbuminuria.

A higher ACR links to a greater risk of kidney disease getting worse, and also to heart disease and stroke.1

What Can Raise ACR Without Kidney Disease

One high result does not mean you have kidney disease. Hard exercise, a urinary infection, or blood in the sample, including menstrual blood, can push the number up for a short time.1 Fever can too.2 Very high blood sugar, very high blood pressure, or heart failure may also raise it.4 Being dehydrated can too. Because a raised ACR must last at least 3 months to count as chronic kidney disease, doctors repeat the test before making a diagnosis.1

Who Should Get Tested

People with diabetes should have this test each year.3 It is also often done for people with high blood pressure, heart disease, obesity, or a family history of kidney failure. In type 1 diabetes, albumin in the urine is often the first sign of diabetic kidney disease, so catching it early matters a lot.3

How ACR Fits With Other Kidney Tests

ACR shows kidney damage. eGFR, a blood test, shows kidney function. Doctors look at both together to stage chronic kidney disease and plan treatment.1 Treating high blood pressure and blood sugar, and taking medicines like ACE inhibitors or ARBs, can lower ACR and help protect the kidneys.1

Note: This tool is for learning and general information. It does not replace advice from a doctor or nurse. Always talk to a health professional about your own test results.

Formulas used

Urine albumin converted to mg/dL
\text{Albumin}_{\text{mg/dL}} = \text{Albumin}_{\text{input}} \times f_{a}, \quad f_{a} = \begin{cases} 1 & \text{mg/dL} \\ 0.1 & \text{mg/L} \end{cases}
Urine creatinine converted to mg/dL
\text{Creatinine}_{\text{mg/dL}} = \text{Creatinine}_{\text{input}} \times f_{c}, \quad f_{c} = \begin{cases} 1 & \text{mg/dL} \\ 1000 & \text{g/dL} \\ 0.011312217 & \mu\text{mol/L} \end{cases}
Albumin-to-creatinine ratio (mg/g)
\text{ACR}_{\text{mg/g}} = \frac{\text{Albumin}_{\text{mg/dL}}}{\text{Creatinine}_{\text{mg/dL}}} \times 1000
ACR in SI units (mg/mmol)
\text{ACR}_{\text{mg/mmol}} = \frac{\text{ACR}_{\text{mg/g}}}{8.8402}
KDIGO albuminuria category 1
\text{Category} = \begin{cases} \text{A1} & \text{ACR} < 30 \\ \text{A2} & 30 \le \text{ACR} < 300 \\ \text{A3} & \text{ACR} \ge 300 \end{cases} \; \text{mg/g}
Severity scale marker position (%)
P = \begin{cases} \dfrac{\text{ACR}}{30} \times 33.333 & \text{ACR} \le 30 \\[6pt] 33.333 + \dfrac{\text{ACR} - 30}{270} \times 33.333 & 30 < \text{ACR} \le 300 \\[6pt] 66.667 + \min\!\left(1, \dfrac{\text{ACR} - 300}{2700}\right) \times 33.333 & \text{ACR} > 300 \end{cases}
Excess above the category threshold
\Delta = \text{ACR} - T, \quad T = \begin{cases} 30 & \text{A2} \\ 300 & \text{A3} \end{cases}

Frequently asked questions

What is a normal albumin creatinine ratio?

An ACR under 30 mg/g (under 3 mg/mmol) is normal to mildly increased.1

In young adults, a normal ACR is under 10 mg/g.2 So a result between 10 and 30 mg/g is still in the normal range, but it can be slightly high for a young person.

How do you collect urine for an ACR test?

Most ACR tests use a single "spot" sample. You pee into a cup at the lab or clinic. No fasting is needed.

A first-morning, midstream sample is preferred.1 Avoid hard exercise the day before and skip the test during your period if you can.1

How do you convert ACR from mg/g to mg/mmol?

Divide mg/g by 8.84.

  • 30 mg/g = 3.4 mg/mmol
  • 300 mg/g = 33.9 mg/mmol
  • 100 mg/g = 11.3 mg/mmol

To go the other way, multiply mg/mmol by 8.84.

What is the formula for albumin creatinine ratio?

ACR (mg/g) = urine albumin (mg/dL) ÷ urine creatinine (mg/dL) × 1000.

The 1000 changes grams of creatinine into milligrams so both numbers use the same scale. Example: 25 mg/dL albumin ÷ 45 mg/dL creatinine × 1000 = 556 mg/g.

Can a high albumin creatinine ratio go back down?

Yes. If the cause was short term, like a fever, dehydration, or hard exercise, the number often drops back to normal on its own.

Even with real kidney damage, ACR can fall. Better blood pressure control, better blood sugar control, weight loss, eating less salt, and medicines like ACE inhibitors, ARBs, or SGLT2 inhibitors can all lower it.1 A falling ACR is a good sign for your kidneys.

Does ACR mean I have kidney disease?

Not by itself. One high result is not a diagnosis.

For chronic kidney disease, the ACR must stay at 30 mg/g or more for at least 3 months.1 Doctors usually want 2 of 3 samples taken over 3 to 6 months to come back high before they call it raised albumin.4 They also look at your eGFR blood test, blood pressure, and health history.

What is the difference between ACR and a urine protein test?

ACR measures only albumin, one specific protein. A urine protein test (PCR, or protein-to-creatinine ratio) measures all proteins together.

ACR is more sensitive. It picks up small leaks that a total protein test misses, so it finds kidney damage earlier. That is why kidney guidelines prefer ACR for screening.2

What can cause a false high albumin in urine?

Several things can raise the number for a short time without kidney disease:

  • Hard exercise in the last 24 hours
  • Fever or any infection
  • Urinary tract infection
  • Dehydration
  • Very high blood sugar
  • Very high blood pressure
  • Menstrual blood or vaginal discharge in the sample
  • Heart failure

This is why doctors repeat the test before making a diagnosis.1

How often should you check your albumin creatinine ratio?

People with diabetes should have an ACR test each year.3 Doctors also often test people with high blood pressure, heart disease, obesity, or a family history of kidney failure.

If you have chronic kidney disease, KDIGO advises checking albumin and eGFR at least once a year, and more often if you are at higher risk.1

Why is ACR important in type 1 diabetes?

In type 1 diabetes, albumin leaking into urine is usually the very first sign of kidney damage, often years before eGFR drops.

Catching it at the A2 stage (30 to 299 mg/g) matters.1 Treatment started early can slow or even reverse the damage. Screening usually begins 5 years after diagnosis, then repeats every year.4

What ACR level is dangerous?

An ACR of 300 mg/g or more (A3) is the most serious band.1 It means a lot of albumin is leaking and links to faster loss of kidney function, plus higher risk of heart attack and stroke.

An ACR over 2200 mg/g is in the nephrotic range.5 A result that high needs prompt care. But any result over 30 mg/g should be checked by a doctor.

Does drinking a lot of water lower your ACR?

No. That is the whole point of the ratio.

Drinking water waters down both the albumin and the creatinine by the same amount. When you divide one by the other, the effect cancels out. So the ratio stays about the same no matter how much you drink.

What foods raise albumin in urine?

No single food causes albumin to leak. But some habits raise the risk over time:

  • Too much salt, which raises blood pressure
  • Lots of sugar and refined carbs, which raise blood sugar
  • Very high protein intake, which strains the kidneys
  • Heavy alcohol use

Eating less salt, more vegetables, and keeping blood sugar steady helps keep ACR low.1

How is ACR used to stage chronic kidney disease?

CKD staging uses two letters and a number. The G number (G1 to G5) comes from your eGFR and shows kidney function. The A letter (A1 to A3) comes from your ACR and shows kidney damage.

So a person might be G2 A3. Both parts together predict risk better than either alone.1 Someone with normal eGFR but A3 albuminuria still has kidney disease.1

Sources

  1. Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney International. 2024;105(4S):S117-S314. doi:10.1016/j.kint.2023.10.018. Accessed September 26, 2026.
  2. Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney International Supplements. 2013;3(1):1-150. Accessed September 26, 2026.
  3. Microalbuminuria test. MedlinePlus, U.S. National Library of Medicine. Accessed September 26, 2026.
  4. American Diabetes Association Professional Practice Committee. 11. Chronic Kidney Disease and Risk Management: Standards of Care in Diabetes—2024. Diabetes Care. American Diabetes Association. 2024;47(Suppl. 1):S219-S230 (Recommendation 11.1a; Screening and Diagnosis of CKD). doi:10.2337/dc24-S011. Accessed October 7, 2026.
  5. Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. Chapter 1: Definition and classification of CKD. Kidney International Supplements. 2013;3(1):19-62 (Albuminuria categories: nephrotic range). doi:10.1038/kisup.2012.64. Accessed October 7, 2026.

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