Albumin-Corrected Calcium Calculator
Corrected calcium = total calcium + 0.02 × (40 − albumin), with calcium in mmol/L and albumin in g/L. This is the simplified Payne equation.
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Calculation
Result
- Albumin-corrected calcium
- 2.28 mmol/L (9.1 mg/dL)
- Uncorrected total calcium
- 2.12 mmol/L
- Albumin
- 32.0 g/L
The correction does not measure ionized calcium and can misclassify results, particularly with low albumin. No universal calcium category is assigned.
The correction does not measure ionized calcium and can misclassify results, particularly with low albumin. No universal calcium category is assigned. Reference ranges are population benchmarks from the cited sources. Laboratories use their own ranges, and interpretation depends on clinical context: discuss the result with your physician.
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How it is calculated
Corrected calcium = total calcium + 0.02 × (40 − albumin), with calcium in mmol/L and albumin in g/L. This is the simplified Payne equation.
Formula
Corrected calcium = total calcium + 0.02 × (40 − albumin), with calcium in mmol/L and albumin in g/L. This is the simplified Payne equation. Ca: mg/dL × 0.2495 = mmol/L; mmol/L ÷ 0.2495 = mg/dL. Albumin: g/dL × 10 = g/L.
Limits of the method
The correction does not measure ionized calcium and can misclassify results, particularly with low albumin. No universal calcium category is assigned.
Sources of the method
- Payne RB et al. Interpretation of serum calcium in patients with abnormal serum proteins. Br Med J, 1973
- Ladenson JH et al. Failure of total calcium corrected for protein, albumin, and pH to correctly assess free calcium status. J Clin Endocrinol Metab, 1978
- Desgagnés N et al. Use of Albumin-Adjusted Calcium Measurements in Clinical Practice. JAMA Netw Open, 2025
This calculation is for reference only and is not medical advice, a diagnosis or a prescription. If you have a medical condition, are pregnant, take medication or have any doubts, discuss the result with a physician or a qualified nutrition professional.
How to use the calculation
Enter the starting values
Corrected calcium = total calcium + 0.02 × (40 − albumin), with calcium in mmol/L and albumin in g/L. This is the simplified Payne equation.
Adjust the parameters
Corrected calcium = total calcium + 0.02 × (40 − albumin), with calcium in mmol/L and albumin in g/L. This is the simplified Payne equation. Ca: mg/dL × 0.2495 = mmol/L; mmol/L ÷ 0.2495 = mg/dL. Albumin: g/dL × 10 = g/L.
Read the result
The correction does not measure ionized calcium and can misclassify results, particularly with low albumin. No universal calcium category is assigned.
Frequently asked questions
What does the calculation show?
Corrected calcium = total calcium + 0.02 × (40 − albumin), with calcium in mmol/L and albumin in g/L. This is the simplified Payne equation.
What limitations apply?
The correction does not measure ionized calcium and can misclassify results, particularly with low albumin. No universal calcium category is assigned.
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What next
Formula breakdowns, biomarker reference ranges and nutrition articles with cited sources are in the NutriFit knowledge base.
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