Absolute Neutrophil Count (ANC) Calculator

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.

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.

Calculate the heart-rate–corrected QT interval (QTc) with three formulae. Bazett (1920): QTc = QT/√RR (classic; over-corrects at high HR, under-corrects at low HR). Fridericia (1920): QTc = QT/RR^(1/3) — more accurate across a wide HR range, preferred for drug/QT studies. Framingham (1992): QTc = QT + 0.154×(1 − RR) — simple linear regression. RR is derived from heart rate (RR = 60/HR) when not provided; QT and QTc in ms. Thresholds: men > 450 ms borderline / > 480 ms prolonged; women > 460 ms borderline / > 480 ms prolonged; > 500 ms markedly prolonged. Derived from Bazett 1920, Fridericia 1920, Sagie/Framingham 1992, AHA 2009, ICH E14, and MDCalc. Not medical advice.

Calculate the glucose-corrected serum sodium to reveal true body tonicity in hyperglycemia. Classic Katz (1973) formula Na_corr = Na + 1.6 × (Glucose − 100)/100 (glucose mg/dL), or Hillier (1999) Na_corr = Na + 2.4 × (Glucose − 100)/100 which is more accurate at very high glucose (Katz tends to underestimate). Glucose unit selectable: mg/dL or mmol/L (reference 5.5 mmol/L). Hyperglycemia shifts water extracellularly and dilutes sodium; the corrected value reflects the real water balance. Corrected Na < 135 indicates true hyponatremia (DKA/HHS with free-water excess, SIADH, GI/renal losses); > 145 indicates true hypernatremia (common in HHS, signals free-water deficit and guides replacement). Derived from Katz NEJM 1973, Hillier 1999, Adrogué NEJM 2000, and MDCalc. Not medical advice.