Iron Deficiency Calculator
HealthEstimate total body iron deficit using the Ganzoni formula from body weight, current and target hemoglobin, and iron stores. An educational reference, not a dosing tool.
Estimated Total Iron Deficit
1,436
What is a Iron Deficit?
The Iron Deficiency Calculator estimates total body iron deficit using the Ganzoni formula, from body weight, the gap between current and target hemoglobin, and an iron stores allowance. This is an educational reference tool, not a dosing calculator for actual treatment.
For a related iron status calculation, see the Transferrin Saturation Calculator.
How to use this Iron Deficit calculator
- Enter the body weight in kilograms.
- Enter the target hemoglobin value.
- Enter the current hemoglobin value.
- Adjust the iron stores reserve allowance if needed (default 500 mg).
- Read the Estimated Total Iron Deficit instantly.
- Remember this is an educational reference only — actual treatment decisions require a qualified healthcare professional.
Formula & Methodology
Total Iron Deficit (mg) = Body Weight (kg) × (Target Hb − Current Hb) × 2.4 + Iron Stores (mg) Worked example — a 65 kg patient with a target hemoglobin of 15 g/dL, current hemoglobin of 9 g/dL, and 500 mg iron stores allowance: Total Iron Deficit = 65 × (15 − 9) × 2.4 + 500 = 65 × 6 × 2.4 + 500 = 936 + 500 = 1,436 mg
Frequently Asked Questions
The Ganzoni formula is a commonly referenced equation for estimating total body iron deficit from body weight, the gap between current and target hemoglobin, and an allowance for iron stores — often cited in discussions of intravenous iron replacement.
The formula multiplies body weight by the hemoglobin deficit (target minus current) and a constant of 2.4, then adds an iron stores allowance (commonly 500 mg) to account for replenishing the body's iron reserves.
The 2.4 constant in the Ganzoni formula reflects blood volume and iron content assumptions used to convert a hemoglobin deficit into an equivalent iron mass requirement.
No — this is an educational reference calculator only. Actual iron replacement therapy dosing must be determined by a qualified healthcare professional based on the complete clinical picture, not a general online calculator.
500 mg is a commonly cited default iron stores allowance in the Ganzoni formula, representing the reserve replenishment component beyond correcting the immediate hemoglobin deficit — though specific clinical protocols may use different figures.
The formula is built around the gap between current and target hemoglobin, since a larger gap implies a greater estimated iron deficit needing correction.
No — this calculator estimates a static iron deficit based on the entered values only. Ongoing blood loss or other factors affecting iron balance would need to be considered separately by a treating physician.
The [Transferrin Saturation Calculator](/transferrin-saturation-calculator/) assesses current iron status from serum iron and TIBC, while this calculator estimates the total deficit that might need correcting — both are related iron-status reference calculations.
This calculator uses kilograms for body weight, g/dL for hemoglobin, and milligrams for iron deficit and iron stores, matching standard units used in the Ganzoni formula.
The Ganzoni formula has been widely referenced in hematology literature for decades as a standard method for estimating total iron deficit in the context of iron replacement discussions.
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