ACR Calculator
A urine albumin of 2 mg/dL with a urine creatinine of 100 mg/dL gives an ACR of 20 mg/g, in the normal to mildly increased range. This ACR calculator computes the urine albumin-to-creatinine ratio from a urine albumin value and a urine creatinine value, then reports the result in mg/g using common published cutoffs. Enter each value as it appears on your urine test and match the unit selector to your lab report.
Quick answer
ACR (mg/g) equals urine albumin in mg/dL times 1000, divided by urine creatinine in mg/dL.
What this tells you
- •ACR (mg/g) equals urine albumin in mg/dL times 1000, divided by urine creatinine in mg/dL.
- •This tool accepts urine albumin in mg/dL or mg/L and urine creatinine in mg/dL or g/L, then converts both to mg/dL before dividing.
- •The result is grouped into normal to mildly increased, moderately increased, or severely increased bands using common published cutoffs.
- •A single spot ACR is a screening estimate, not a diagnosis of kidney disease.
How to Use
- 1Enter your urine albumin value and select whether it is in mg/dL or mg/L.
- 2Enter your urine creatinine value and select whether it is in mg/dL or g/L.
- 3Calculate to see the ACR in mg/g and its interpretation band.
- 4Compare the result with your lab reference range, since a single spot sample can vary from day to day.
How It Works
Formula
ACR (mg/g) = (urine albumin in mg/dL x 1000) / urine creatinine in mg/dL
mg/L albumin converts to mg/dL by dividing by 10
g/L creatinine converts to mg/dL by multiplying by 100
Example: (2 mg/dL x 1000) / 100 mg/dL = 20 mg/gThe calculator first converts both inputs to mg/dL using standard concentration conversions. It then multiplies the urine albumin concentration by 1000 and divides by the urine creatinine concentration, which produces a result in the milligrams of albumin per gram of creatinine unit used on most lab reports and in common kidney health guidelines.
Calculation note: values are processed in the order shown above, using the current input units.
Worked Examples
Normal-range example in mg/dL
2 mg/dL times 1000, divided by 100 mg/dL, equals 20 mg/g, below the 30 mg/g cutoff.
Moderately increased example with mixed units
150 mg/L converts to 15 mg/dL and 1 g/L converts to 100 mg/dL, so 15 mg/dL times 1000, divided by 100 mg/dL, equals 150 mg/g.
Common ACR Interpretation Bands
These published albuminuria categories are used alongside eGFR for kidney health screening.
| Category | ACR range | What it generally suggests |
|---|---|---|
| Normal to mildly increased (A1) | Below 30 mg/g | Generally considered within the normal screening range |
| Moderately increased (A2) | 30 to 300 mg/g | May indicate early kidney changes and often prompts a repeat test |
| Severely increased (A3) | Above 300 mg/g | Associated with a higher likelihood of kidney damage and usually needs clinical follow-up |
A clinician interprets ACR together with eGFR and other test results, not as a stand-alone diagnosis.
Common mistakes
- Entering urine creatinine as zero or leaving it blank, which makes the ratio undefined.
- Pasting a mg/L albumin value into the field without switching the unit selector to mg/L.
- Treating a single high spot ACR as a confirmed diagnosis instead of a screening signal that often needs a repeat test.
Limitations
This calculator assumes the urine albumin and urine creatinine values come from the same urine sample and applies standard unit conversions between mg/dL, mg/L, and g/L. It does not account for exercise, dehydration, urinary tract infection, menstruation, fever, or other factors that can temporarily raise urine albumin. A single ACR estimate does not replace a repeat test or a full eGFR-based kidney health assessment.