🧪 Delta Ratio (Delta-Delta) Calculator
Calculate the delta ratio (delta-delta) to uncover mixed metabolic acid–base disorders.
Delta Ratio (Delta-Delta) Calculator
Measured anion gap (mmol/L)
Bicarbonate (HCO₃⁻) (mmol/L)
When to use
Detect a coexisting normal-gap acidosis or metabolic alkalosis in high-anion-gap acidosis.
How it works
Delta ratio = (AG − 12) / (24 − HCO₃). < 0.4 added NAGMA; 0.4–1 combined; 1–2 pure HAGMA; > 2 added metabolic alkalosis.
Key points
- Compares the rise in anion gap with the fall in bicarbonate.
- Reference AG and HCO₃ values are lab-dependent.
- Interpret with the full acid–base picture.
References
Decision support for licensed clinicians only; not a substitute for clinical judgement, diagnosis or local protocols.