Diabetic Ketoacidosis (DKA) Calculator — Severity & Electrolytes
Enter blood glucose, serum pH, and electrolytes to classify DKA severity by ADA 2009 criteria (mild / moderate / severe) and instantly compute the anion gap, hyperglycaemia-corrected sodium, expected pCO₂ by Winter's formula, and effective serum osmolality.
mg/dL
mEq/L
mEq/L
mEq/L
Elevated (>12 mEq/L) — consistent with DKA
- 1
Sum of measured anions (Cl⁻ + HCO₃⁻)
100 + 12 = 112The denominator of the anion gap: measured negative ions in serum. - 2
Anion gap
Na⁺ − (Cl⁻ + HCO₃⁻) = 138 − 112 = 26Normal range 8–12 mEq/L. Above 12 suggests unmeasured anions (ketoacids in DKA).
How does this calculator work?
Enter glucose, pH, Na⁺, Cl⁻, and HCO₃⁻ to classify DKA severity: Mild (pH 7.25–7.30, HCO₃ 15–18), Moderate (pH 7.0–7.24, HCO₃ 10–14), or Severe (pH <7.0, HCO₃ <10). The anion gap (Na − Cl − HCO₃), hyperglycaemia-corrected sodium, expected pCO₂ by Winter's formula, and effective osmolality are computed instantly. For clinical reference only.
Formula
How this is calculated
Diabetic ketoacidosis occurs when insulin deficiency drives uncontrolled lipolysis and hepatic ketone production, resulting in a high anion-gap metabolic acidosis. The ADA 2009 criteria classify severity by venous pH and serum bicarbonate: Mild (pH 7.25–7.30, HCO₃ 15–18 mEq/L), Moderate (pH 7.0–7.24, HCO₃ 10–14 mEq/L), and Severe (pH <7.0, HCO₃ <10 mEq/L). Blood glucose ≥ 250 mg/dL is also required; euglycaemic DKA (e.g. on SGLT-2 inhibitors) is a rarer exception handled separately in clinical practice.
The anion gap (Na⁺ − Cl⁻ − HCO₃⁻) quantifies unmeasured anions from accumulated ketoacids; a value above 12 mEq/L signals a high-gap acidosis consistent with DKA. Because hyperglycaemia draws water into the extracellular space by osmosis, measured sodium is artefactually low; the Katz correction adds 1.6 mEq/L for each 100 mg/dL of glucose above 100 to estimate the true sodium. Effective serum osmolality (2 × Na + glucose/18) captures the hyperosmolar load without urea, which crosses membranes freely and does not drive fluid shifts. Winter's formula (expected pCO₂ = 1.5 × HCO₃ + 8 ± 2 mmHg) checks respiratory compensation: a measured pCO₂ above the range implies a concurrent respiratory acidosis, below implies a respiratory alkalosis.
This tool is for clinical reference and education only and is based on ADA 2009 guidelines and standard physiology texts. Actual DKA diagnosis and management require laboratory confirmation, clinical assessment, and physician oversight.
Frequently asked questions
The ADA 2009 criteria require all three: blood glucose >250 mg/dL, serum bicarbonate ≤ 18 mEq/L or venous pH <7.30, and positive serum or urine ketones. Severity is then sub-classified into mild, moderate, and severe by pH and bicarbonate thresholds.
Hyperglycaemia creates an osmotic gradient that draws water from cells into the extracellular space, diluting sodium. The Katz formula adds approximately 1.6 mEq/L to measured sodium for each 100 mg/dL that glucose exceeds 100 mg/dL. This corrected value reflects the sodium that will be present once glucose is lowered during treatment.
Winter's formula predicts the expected pCO₂ if the lungs are compensating normally for a simple metabolic acidosis: expected pCO₂ = 1.5 × HCO₃ + 8 (± 2 mmHg). A measured pCO₂ above the predicted range suggests a concurrent respiratory acidosis (inadequate ventilation); below suggests a concurrent respiratory alkalosis (e.g. sepsis, anxiety, or salicylate toxicity).
Also known as
TG we-Calculate Editorial Team. (2026). Diabetic Ketoacidosis (DKA) Calculator — Severity & Electrolytes [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/diabetic-ketoacidosis-calculator
TG we-Calculate Editorial Team. "Diabetic Ketoacidosis (DKA) Calculator — Severity & Electrolytes." TG we-Calculate. 2026. https://we-calculate.com/calculator/diabetic-ketoacidosis-calculator.
TG we-Calculate Editorial Team, "Diabetic Ketoacidosis (DKA) Calculator — Severity & Electrolytes," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/diabetic-ketoacidosis-calculator
@misc{wecalculate_diabetic_ketoacidosis_calculator, title = {Diabetic Ketoacidosis (DKA) Calculator — Severity & Electrolytes}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/diabetic-ketoacidosis-calculator}}, year = {2026}, note = {TG we-Calculate} }
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