Corrected Calcium Calculator
Calculate corrected calcium levels based on albumin. Critical for patients with hypoalbuminemia.
Total calcium levels can be misleading in patients with low albumin. Since roughly 40-50% of calcium is bound to albumin, low albumin levels can make calcium appear falsely low.
Calculator Inputs
Results
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How It Works
This calculator uses the Payne formula to estimate what the calcium level would be if the albumin were normal (4.0 g/dL).
Worked example
Patient with Calcium 8.0 and Albumin 2.5
4.0 - 2.5= 1.51.5 × 0.8= 1.28.0 + 1.2= 9.2 mg/dLTips & Best Practices
- •Use this when albumin is < 4.0 g/dL.
- •If ionized calcium is available, that is the gold standard and correction is not needed.
- •Normal corrected calcium range is typically 8.5 - 10.2 mg/dL.
Frequently Asked Questions
What is the formula?
Corrected Ca = Measured Ca + 0.8 * (4.0 - Albumin)
Guides & Articles
Due Date From Ovulation or Conception Date
Add 266 days to an ovulation date or a conception date. A worked example, why both dates use the same rule, and when the period method is the better start.
How Accurate Are Pregnancy Due Dates?
A due date is the 40-week mark from a period, or 38 weeks from ovulation. Most births are not on that exact day. What moves the estimate, and what replaces it.
How Many Days Is a Pregnancy?
280 days (40 weeks) from the last menstrual period, or 266 days (38 weeks) from conception. Same model, different starting point, plus the term labels clinicians use.
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