Hematology

Total Iron Deficit (Ganzoni Equation)

Calculates the total iron deficit for intravenous iron replacement.

Parameters

g/dL
g/dL

Total Iron Deficit (Ganzoni Equation) Result

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FormulaTotal Iron Deficit (mg) = Body Weight (kg) × (Target Hb - Actual Hb) [g/dL] × 2.4 + Iron stores (500 mg for adults, 15 mg/kg for children <35 kg).

Clinical Pearls

Used to plan the total dosing of IV iron formulations (e.g., iron sucrose, ferric carboxymaltose, iron dextran).

Limitations

The formula often underestimates iron requirements in women and those with ongoing blood loss (e.g., heavy menstrual bleeding or GI bleeds). Many newer IV iron products use simpler dosing grids (e.g., based on weight tiers and Hb levels) rather than the Ganzoni equation.