Iron Dosing Calculator (Iron Deficit)

Calculates estimated elemental iron deficit using the Ganzoni equation and converts the result into practical IV iron treatment plans for common products including Venofer, Injectafer, Monoferric, Feraheme, and Ferrlecit.

Ganzoni equation

Total iron deficit (mg) = weight (kg) × [target Hb − current Hb] × 2.4 + iron stores

Default iron stores = 500 mg for adults. Ganzoni remains a commonly used method to estimate iron deficit, but final IV iron dosing should follow product-specific prescribing information. Ferritin and TSAT are optional interpretation fields and do not alter the Ganzoni dose calculation.

Calculator inputs

Clinical context

Pregnancy defaults to target Hb 11 g/dL. Postpartum and nonpregnant default to 12 g/dL.

Weight*

70.0 kg

Current Hb (g/dL)

Target Hb (g/dL)

Iron stores (mg)

* Actual body weight. In pregnancy, consider pre-pregnancy weight if substantial gestational weight gain may overestimate deficit.
Iron studies (interpretation only)

Ferritin and TSAT are optional. They do not alter the Ganzoni dose calculation.

Ferritin (optional, ng/mL)

TSAT (optional, %)

Ferritin and TSAT are optional and do not change the Ganzoni dose calculation.

Preferred Venofer dose per visit

Common outpatient and pregnancy practice often uses 200 mg per visit. Product labeling includes CKD-based schedules of 100 mg, 200 mg, and selected higher divided doses.

Clinical notes

Use clinical judgment. Consider confirming iron deficiency with ferritin and iron studies when the diagnosis is uncertain, and do not use this tool in iron overload states. Product-specific labeling, infusion center policy, and hypersensitivity precautions should always be reviewed before treatment.

Estimated iron deficit

836 mg

Ganzoni estimate

Rounded treatment target

900 mg

Rounded to practical dosing

Hb gap

2.0 g/dL

Target − current Hb

Iron stores added

500 mg

Reservoir component

Estimated deficit fits within a typical 1,000 mg replacement course. Venofer at 200 mg per visit would require 5 visits.

Venofer (iron sucrose)

Injectafer (ferric carboxymaltose)

Monoferric (ferric derisomaltose)

Feraheme (ferumoxytol)

Ferrlecit (sodium ferric gluconate)

Interpretation

Clinical summary

Reminder: IV iron products are not interchangeable milligram-for-milligram in terms of labeled administration schedules. This calculator estimates elemental iron need and then maps that estimate to common product-specific regimens.

References and dosing notes

Ganzoni equation Iron sucrose Ferric carboxymaltose Ferric derisomaltose Ferumoxytol Ferric gluconate

Ganzoni AM. Intravenous iron-dextran: therapeutic and experimental possibilities. Schweiz Med Wochenschr. 1970;100(7):301-303.
Ganzoni equation: Total iron deficit (mg) = body weight (kg) × [target Hb − actual Hb in g/dL] × 2.4 + depot iron, commonly 500 mg in adults.
Venofer prescribing information and Venofer dosing information.
Injectafer prescribing information and Injectafer dosing information.
Monoferric prescribing information.
Feraheme prescribing information.
Ferrlecit prescribing information.

This calculator is intended as a bedside planning tool and should be reconciled with the product label, infusion center protocol, and patient-specific contraindications.