This version was machine-translated from German and has not been medically reviewed. The authoritative version is the German version.

Acid-base compensation calculator

Primary disorder from pH, pCO₂ and HCO₃ – expected compensation according to Berend 2014 and anion gap

Blood gas analysis
Electrolytes

Scientific basis

Reference range of your own laboratory

Anion gap and delta ratio depend on the measurement method for sodium and chloride. The reference values used here (AG 12, HCO₃⁻ 24) are conventions of the cited papers; your own laboratory's reference range takes precedence.

Calculation aid for healthcare professionals: the calculator reproduces what the sources cited assign to the inputs. Clinical assessment and every treatment decision remain with the treating physician. Inputs and results are not stored.

Frequently asked questions

Acid-base compensation calculator: What does this calculator compute?

Uses pH, pCO₂ and bicarbonate to determine the primary acid-base disorder, calculates the expected compensation (metabolic: Winter formula or 0.7 × HCO₃ + 21; respiratory acute/chronic: bicarbonate change per 10 mmHg) according to Berend et al. 2014 and thus detects additional disorders; with sodium and chloride also anion gap and delta ratio.

Acid-base compensation calculator: Which sources is this calculator based on?

Kraut JA, Madias NE: Serum anion gap: its uses and limitations in clinical medicine (Clin J Am Soc Nephrol 2:162–174) (2007); Figge J, Jabor A, Kazda A, Fencl V: Anion gap and hypoalbuminemia (Crit Care Med 26:1807–1810) (1998); Wrenn K: The delta (Δ) gap: an approach to mixed acid-base disorders (Ann Emerg Med 19:1310–1313) (1990); Albert MS, Dell RB, Winters RW: Quantitative displacement of acid-base equilibrium in metabolic acidosis (Ann Intern Med 66:312–322) – “Winter formula” (1967); Berend K, de Vries AP, Gans RO: Physiological approach to assessment of acid-base disturbances (N Engl J Med 371:1434–1445) – Table 2: Expected compensatory responses (2014); Kraut JA, Madias NE: Metabolic acidosis: pathophysiology, diagnosis and management (Nat Rev Nephrol 6:274–285) (2010)