Acid-Base

Winters' Formula Calculator

Expected PaCO₂ for a metabolic acidosis (Winter’s formula); a PaCO₂ outside the range means a second, respiratory disorder.

Reviewed by Alex G, BSN, RN, CEN, CCRN, CMC, NREMT-P · From the Reference tab of the app

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Formula

Expected PaCO₂ = (1.5 × HCO₃) + 8 ± 2

How it is used

If the measured PaCO₂ is HIGHER than expected: Concomitant Respiratory Acidosis.
If the measured PaCO₂ is LOWER than expected: Concomitant Respiratory Alkalosis.

Same formula as the app. Open it in the web app.

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For education and exam preparation only. Follow your institution’s protocols. For education and exam preparation only. Verify results independently and follow your local protocols and medical direction. Not a substitute for clinical judgment.