Iron Deficit Calculator (Ganzoni)

Ganzoni 1970 total iron deficit: weight x (target Hb - current Hb) x 2.4 + iron stores (default stores applied when no override given).

Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.

Example

Weight
70 kg
Current Hb
9 g/dL
Target Hb
15 g/dL

Result: Total iron deficit 1508 mg (1008 mg + 500 mg stores).

The tool opens with these values already filled in. Replace them with your own.

What you enter

  • Weight
  • Current Hb
  • Target Hb
  • Iron stores override

What this is

Apply the Ganzoni equation (Ganzoni 1970) to estimate total body iron deficit in milligrams from body weight, current hemoglobin, and target hemoglobin: deficit = weight(kg) * (target Hb - current Hb) * 2.4 + iron stores (typically 500 mg in adults). Sophie Well returns the total deficit so the prescriber can compare it to a single-dose IV iron formulation's maximum dose and plan one or two infusions instead of guessing.

When to use it

Use this when ordering IV iron for iron-deficiency anemia where the patient cannot tolerate, has failed, or has malabsorption issues with oral iron. The Ganzoni number tells you whether the patient needs a single 1000 mg ferric carboxymaltose infusion, a split course, or a higher cumulative dose. It is not a substitute for confirming iron deficiency by ferritin and transferrin saturation before treating.

How this is calculated

Ganzoni AM. Schweiz Med Wochenschr 1970;100:301-303. Read the source ↗

A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.

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Built by Clay Good. Source on GitHub.