Calculate TSAT, UIBC, and TIBC from transferrin and serum iron, classify iron panel patterns for IDA vs ACD, compute Ganzoni iron deficit, and adjust ferritin for inflammation.
Transferrin is the primary iron transport protein in the blood, and its measurement — along with serum iron, total iron-binding capacity (TIBC), and ferritin — forms the foundation of the iron studies panel used to diagnose and classify iron disorders. Transferrin saturation (TSAT), calculated as serum iron divided by TIBC (or transferrin × 1.41), is one of the most clinically actionable parameters in the iron workup.
This calculator computes transferrin saturation, unsaturated iron-binding capacity (UIBC), inter-converts between transferrin and TIBC, and employs pattern recognition to classify the iron panel into iron deficiency anemia (IDA), anemia of chronic disease (ACD), mixed IDA/ACD, iron overload, and other patterns. It adjusts ferritin interpretation when C-reactive protein (CRP) indicates active inflammation, using the divide-by-3 rule accepted in clinical practice.
For patients with confirmed iron deficiency, the Ganzoni formula calculates total iron deficit in milligrams, guiding IV iron dosing. Understanding transferrin as a negative acute-phase reactant and ferritin as a positive acute-phase reactant is critical for accurate interpretation in the setting of infection, malignancy, autoimmune disease, or other inflammatory states that confound the standard iron panel.
This calculator automates the complete iron panel workup: inter-converting transferrin and TIBC, computing TSAT and UIBC, classifying iron panel patterns, adjusting ferritin for inflammation, and calculating Ganzoni iron deficit — replacing manual interpretation of multiple lab values with instant pattern recognition. Keep these notes focused on your operational context. Tie the context to the calculator’s intended domain.
TSAT (%) = (Serum Iron / TIBC) × 100. TIBC ≈ Transferrin × 1.41 µg/dL. UIBC = TIBC − Serum Iron. Ganzoni Iron Deficit (mg) = Weight(kg) × (Target Hb − Actual Hb)(g/dL) × 2.4 + 500.
Result: TIBC 564, TSAT 5.3%, Pattern: Iron Deficiency Anemia
Markedly low TSAT (5.3%), very low ferritin (8 ng/mL), and elevated TIBC (564 µg/dL from high transferrin) create the classic IDA pattern: high transferrin production compensating for iron deficiency, with depleted stores confirmed by low ferritin and low serum iron.
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TIBC measures the total capacity of serum to bind iron (µg/dL), while transferrin is the actual protein concentration (mg/dL). They are proportional: TIBC ≈ transferrin × 1.41. TIBC is a functional assay; transferrin is a direct protein measurement. Both provide equivalent clinical information.
Serum iron fluctuates widely with diet, diurnal variation (highest in AM), and meals. TSAT normalizes iron to its carrier capacity, providing a more stable indicator of iron availability. TSAT <16% indicates functional iron deficiency regardless of absolute iron level.
Inflammation increases ferritin (acute-phase reactant, may mask deficiency), decreases transferrin (negative acute-phase reactant), and reduces serum iron via hepcidin-mediated iron sequestration. This creates the ACD pattern: low iron, low TIBC, "normal" or elevated ferritin despite possible true iron deficiency.
Functional iron deficiency occurs when iron stores (ferritin) may be adequate but iron delivery to the bone marrow is insufficient for erythropoiesis, typically when TSAT <20%. This is common in CKD patients on erythropoietin, where iron demands exceed supply despite normal ferritin.
Use the Ganzoni formula to calculate total IV iron replacement needs when oral iron has failed or is contraindicated (IBD, malabsorption, CKD, intolerance). The formula accounts for both the hemoglobin deficit and iron store replenishment (500 mg for stores).
TSAT >45% warrants investigation for iron overload, and TSAT >60% is highly suggestive of hereditary hemochromatosis (especially with elevated ferritin >300 in men or >200 in women). HFE gene testing should be performed when TSAT is persistently elevated.