Albumin Creatinine Ratio Calculator

Albumin Creatinine Ratio Calculator for Nephrology. A1 is below 30 mg/g, A2 is 30 through 300, and A3 is above 300 with no decimal gaps. A result of 300.5 is A3; zero measured albumin yields zero if creatinine is positive.

For shared guidance on choosing a tool and documenting results, read the clinical calculator workflow.

How this calculator works

ACR in mg/g = urine albumin in mg/L / [urine creatinine in mmol/L x 0.1131]. For US input, albumin mg/dL is multiplied by 10 and creatinine mg/dL divided by 11.31. Both analyte-specific conversions now govern unit changes.

When to use this calculator

Quantifying paired urine albumin and creatinine concentrations and describing albuminuria category.

Inputs used

  • Urine albumin (mg/L; US mg/dL)
  • Urine creatinine (mmol/L; US mg/dL)

Clinical interpretation

A1 is below 30 mg/g, A2 is 30 through 300, and A3 is above 300 with no decimal gaps. A result of 300.5 is A3; zero measured albumin yields zero if creatinine is positive.

Worked example

Urine albumin 4.5 mg/dL and creatinine 90 mg/dL produce 50 mg/g. The same inputs are 45 mg/L and approximately 7.9576 mmol/L. The former approximately 1000-fold conversion error is removed.

Limitations and safety notes

Transient albuminuria and sampling conditions affect interpretation. One ACR does not establish chronic kidney disease, staging, treatment or referral. Zero creatinine is invalid and repeat assessment may be needed.

Frequently asked questions

Can 300.5 mg/g fall between categories?

No. Every result above 300 is A3. The category is computed from the unrounded value.

What does this result leave unresolved?

Transient albuminuria and sampling conditions affect interpretation. One ACR does not establish chronic kidney disease, staging, treatment or referral. Zero creatinine is invalid and repeat assessment may be needed.

References

  • https://kdigo.org/wp-content/uploads/2024/03/KDIGO-2024-CKD-Guideline.pdf

Editorial review and citation methodology

Maintained by the Quick Medical Calculator Editorial Team. Content record date: September 9, 2026. A content date is not evidence of independent clinical review. Individual clinical sign-off is not recorded on this page.

  • Prefer original validation studies for scoring systems and prediction tools.
  • Use current specialty society guidance, transplant allocation policy, public health guidance, or regulator resources when they govern clinical use.
  • Include limitations and safety notes when a calculator is population-specific, context-dependent, or unsuitable as a standalone decision tool.

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