About this calculator
The Ganzoni formula estimates total iron deficit from body weight and hemoglobin gap. It is commonly used for IV iron planning discussions, but actual treatment depends on diagnosis, iron studies, product labeling, infusion limits, and monitoring.
Uses the Ganzoni equation: total iron deficit (mg) = body weight (kg) × (target Hb − actual Hb in g/dL) × 2.4 + depot iron. Actual product dosing and maximum single dose vary.
Source-mapped educational formula
Ganzoni iron deficit is an estimate and does not choose an iron product, infusion protocol, monitoring plan, or safety setting.
Formula and method
Total iron deficit (mg) = weight (kg) × (target Hb − actual Hb) × 2.4 + depot iron (mg). If actual Hb is above the target, the hemoglobin-gap component is set to zero.
Limitations and when not to rely on this result
- Ganzoni iron deficit is an estimate and does not choose an iron product, infusion protocol, monitoring plan, or safety setting.
- Pregnancy, active bleeding, inflammation, kidney disease, heart disease, allergies, and very low hemoglobin need clinician-directed care.
- Do not use this page to self-prescribe iron therapy.
Frequently asked questions
Does this prescribe an IV iron dose? +
No. It estimates iron deficit. Product-specific dose limits, infusion schedules, diagnosis, and monitoring are clinical decisions.
What does the 2.4 factor mean? +
It approximates blood volume and hemoglobin iron content for converting a hemoglobin gap into an iron requirement.
What depot iron value should I use? +
Many adult examples use 500 mg, but protocols vary by patient size, pregnancy, kidney disease, inflammation, and product.
Can this be used in children? +
Only for education. Pediatric iron therapy should use pediatric protocols and clinician supervision.
What labs matter besides hemoglobin? +
Ferritin, transferrin saturation, MCV, CRP/inflammation, bleeding source, kidney disease, and pregnancy status may matter.