How this calculator works
The Ganzoni equation estimates iron needed to raise hemoglobin and replenish a conventional store allowance. This page is limited to adults at least 35 kg and uses the published 500 mg allowance for that weight group. The target hemoglobin is an input, not a recommendation. Iron deficiency must be confirmed first. The result is a total deficit estimate, not a product dose, infusion schedule, oral dose or permission to self-treat. The result is an estimate for information only and is not medical advice.
Formula
Total iron deficit (mg) = weight (kg) x [target Hb - actual Hb] (g/dL) x 2.4 + 500 mg. With Hb in g/L the coefficient is 0.24.
Worked example
At 70 kg, current Hb 9 g/dL and target 15 g/dL, the hemoglobin deficit requires 1008 mg; adding 500 gives 1508 mg. At 80 kg, Hb 80 g/L and target 150 g/L, the total is 1844 mg.
Advertisement
Frequently asked questions
Does this diagnose iron deficiency?
No. A low hemoglobin has many possible causes; laboratory assessment is needed.
Is the total an amount to take at once?
No. Product limits, route, timing and monitoring require a clinician and are outside this calculator.
Why are smaller patients excluded?
Children and lower body weights use different store assumptions and clinical protocols. This page covers the adult equation only.