Osmolar Gap Calculator

Calculate the Absolute Neutrophil Count (ANC) = WBC × (segmented % + band %) / 100. Unit selectable: cells/µL or ×10⁹/L (1 ×10⁹/L = 1000 cells/µL). Adult reference ≥ 1500 cells/µL. Neutropenia risk strata: mild 1000–1500, moderate 500–1000, severe < 500 (agranulocytosis < 200) — high risk of serious infection, and febrile neutropenia is a medical emergency. Clinical uses: chemotherapy cycles typically require ANC ≥ 1500 to proceed and ≥ 500 for discharge from protective isolation; carbimazole/clozapine monitoring; congenital neutropenia workup. Neutrophilia > 7500 suggests bacterial infection, inflammation, steroids, or a myeloproliferative neoplasm. If only segmented % is reported, set band % to 0; if the instrument reports an absolute neutrophil count directly (NE#), this tool is not needed. Based on ASCO/IDSA neutropenia guidance, Boxer ASH 2012, and MDCalc. Not medical advice.

Calculate the serum Anion Gap (AG) to classify metabolic acidosis. Standard formula AG = Na⁺ − Cl⁻ − HCO₃⁻ (mmol/L), or AG = Na⁺ + K⁺ − Cl⁻ − HCO₃⁻ with optional potassium. A high AG (≈ >12, or >20 with K⁺) indicates accumulation of unmeasured anions (lactic acidosis, ketoacidosis, renal failure, and toxins such as methanol/ethylene glycol, salicylates — mnemonic GOLD-MARK). A normal AG (8–12) during metabolic acidosis points to a hyperchloremic (normal-anion-gap) acidosis: diarrhea, renal tubular acidosis, saline resuscitation. A low AG (<3–6) is usually hypoalbuminemia, also hypercalcemia/hypermagnesemia, lithium, cationic IgG paraproteins, or bromide pseudo-hyperchloraemia. Optional albumin correction AG_corrected = AG + 2.5 × (4.0 − albumin g/dL) avoids missing a high-AG acidosis in hypoalbuminemia. Derived from Kraut CJASN 2007, Figge 1998, and MDCalc. Interpret with blood gas and full clinical context. Not medical advice.

Complete ABG analysis: pH, primary disorder, compensation (Winter's formula), anion gap ± albumin correction, delta ratio for mixed disorder detection. Derived from Emmett 2016, Kraut 2007, Rastegar 2007, LITFL, MDCalc, and Adrogué 1998. Not medical advice.

Calculate the albumin-corrected total calcium to avoid missing true hypocalcemia or hypercalcemia in hypoalbuminemia. Conventional formula (calcium mg/dL, albumin g/dL): Ca_corr = Ca + 0.8 × (4.0 − Albumin). SI formula (calcium mmol/L, albumin g/L): Ca_corr = Ca + 0.02 × (40 − Albumin). Roughly 40% of circulating calcium is albumin-bound, so low albumin lowers the measured total without changing the physiologically active ionized fraction. Corrected reference range ≈ 8.5–10.5 mg/dL (2.15–2.60 mmol/L). Low → true hypocalcemia (hypoparathyroidism, vitamin-D deficiency, CKD, hypomagnesemia, citrated transfusion, pancreatitis, sepsis); high → true hypercalcemia (primary hyperparathyroidism, malignancy/PTHrP, myeloma, vitamin-D intoxication, thiazides, immobilization, granulomatous disease). When albumin is markedly abnormal or acid-base is deranged, ionized calcium remains the gold standard. Based on Payne BMJ 1973 and MDCalc. Not medical advice.