Transferrin & Iron Studies Calculator (TSAT, UIBC)
Calculate transferrin saturation (TSAT) and UIBC from serum iron & TIBC, automatic unit conversion (µg/dL ⇄ µmol/L), and get an integrated interpretation panel from TSAT + ferritin. All calculations run 100% in your browser — no data is sent anywhere.
Medical disclaimer: This tool is for education and is not a substitute for professional medical advice. Its results are not a diagnosis. Always discuss your laboratory results with a doctor or qualified healthcare professional.
Laboratory result input
Iron circulating in the blood, bound to transferrin.
Maximum iron-binding capacity of transferrin.
Body iron stores. 1 ng/mL = 1 µg/L.
Sets the TSAT overload cutoff (>45% male, >50% female).
Calculation results
TSAT (transferrin saturation)
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UIBC
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Serum iron
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TIBC
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Ferritin
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Warning: serum iron exceeds TIBC (TSAT > 100%) — physiologically impossible. Double-check your input values and units.
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Formulas: TSAT = serum iron / TIBC × 100% · UIBC = TIBC − serum iron. Interpretation bands follow standard clinical guidelines; each laboratory’s reference ranges may differ.
Important: The interpretation above only shows common result patterns, not a diagnosis. Serum iron fluctuates throughout the day and ferritin can be raised by inflammation — medical decisions always require a doctor’s evaluation.
Formulas & worked example
TSAT = (serum iron ÷ TIBC) × 100% · UIBC = TIBC − serum iron
Iron unit conversion: 1 µg/dL = 0.179 µmol/L. Example: 60 µg/dL × 0.179 = 10.74 µmol/L.
Common reference range table (adults)
Parameter
Male
Female
Serum iron
60–170 µg/dL (10.7–30.4 µmol/L)
50–150 µg/dL (9.0–26.9 µmol/L)
TIBC
240–450 µg/dL (43.0–80.6 µmol/L)
TSAT
20–50%
20–50%
Ferritin
30–300 ng/mL
15–150 ng/mL
UIBC
150–375 µg/dL (derived: TIBC − serum iron)
Reference ranges vary between laboratories — the figures above are commonly used general ranges; always compare with the range printed on your lab result sheet. Calculator interpretation bands: TSAT < 16% deficient · 16–45% normal · > 45% (male) / > 50% (female) consider overload · ferritin < 30 ng/mL deficient · 30–300 normal · > 300 consider overload/inflammation.
Remember: This calculator does not diagnose anemia or any condition. If your results fall outside the normal range or you have symptoms (fatigue, paleness, dizziness), consult a doctor promptly.
Frequently asked questions (FAQ)
What is transferrin saturation (TSAT)?
Transferrin saturation (TSAT) is the percentage of transferrin protein in the blood that is currently carrying iron. TSAT is calculated as: (serum iron / TIBC) x 100%. TSAT reflects the current iron availability for red blood cell production, not the amount of body iron stores.
How does TSAT differ from ferritin?
TSAT reflects iron currently being transported (availability) and can fluctuate throughout the day, while ferritin reflects body iron stores (storage). Ferritin usually falls first as iron stores begin to deplete, even before serum iron and TSAT follow.
Why is my ferritin normal even though my TSAT is low?
Ferritin is an acute phase reactant: its level can rise with infection, inflammation, liver disease, or other chronic conditions, masking iron deficiency. A TSAT below 16% combined with normal or high ferritin is consistent with functional iron deficiency or anemia of chronic disease. Discuss with your doctor for further evaluation.
Should I fast before an iron test?
Serum iron has diurnal variation (it changes throughout the day) and can be affected by recently eaten food. Many laboratories ask for fasting and morning blood draws for consistent results. Follow the preparation instructions from your laboratory or doctor.
When do iron studies need to be repeated?
Repeat testing is generally done as advised by your doctor, for example to monitor response after iron therapy or to evaluate chronic conditions, usually within weeks to months. Do not repeat tests or start supplements based on this calculator alone without medical guidance.
What is UIBC?
UIBC (unsaturated iron binding capacity) is the unfilled iron-binding capacity: UIBC = TIBC - serum iron. UIBC rises in iron deficiency (many empty spots on transferrin) and falls in iron overload or chronic inflammation.
How do I convert ug/dL to umol/L for iron?
For serum iron and TIBC, 1 ug/dL = 0.179 umol/L (based on iron’s molecular weight of 55.845). Example: 60 ug/dL equals 10.74 umol/L. This calculator converts automatically when you change the input unit.
My TSAT is high — does that mean iron overload?
A TSAT above 45% (male) or 50% (female), especially with high ferritin, is consistent with an iron overload pattern and needs a doctor’s evaluation, such as hemochromatosis screening if clinically indicated. Do not conclude a diagnosis yourself from a single number.
Why do women of childbearing age often have low TSAT?
Menstruation causes routine blood loss that depletes iron stores, so women of childbearing age are more prone to iron deficiency. The common pattern is low ferritin and low TSAT. If you have symptoms such as fatigue or paleness, discuss them with your doctor.
Can this calculator diagnose iron deficiency anemia?
No. This calculator is an educational aid for computing TSAT and UIBC and showing common result patterns. Diagnosing iron deficiency anemia requires a doctor’s evaluation, including hemoglobin, a complete blood count, and clinical context. Always discuss your laboratory results with a medical professional.
Related tools:Mentzer Index Calculator — distinguishes thalassemia trait vs iron deficiency anemia from MCV and RBC count.
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