Total Iron Binding Capacity (TIBC) Unit Converter
Total Iron Binding Capacity (TIBC) Unit Converter
Convert TIBC between µg/dL, µg/L and µmol/L, and see where the value sits against the adult reference interval.
Total Iron Binding Capacity (TIBC) converter
Mass ⇄ molarTIBC 330 µg/dL
Formula and conversion factor
µg/dL = µmol/L ÷ 0.1791
- 0.1791
- TIBC is expressed as iron-binding capacity, so it uses the atomic weight of iron, 55.845 g/mol
- µg/L
- µg/dL × 10
Worked example
TIBC 330 µg/dL
330 × 0.1791 = 59.09 µmol/L
330 µg/dL = 3300 µg/L
Reference ranges and interpretation
| Pattern | TIBC µg/dL | Typical cause |
|---|---|---|
| Reference interval | 240 – 450 | — |
| Raised | > 450 | Iron deficiency, pregnancy, oral contraceptives |
| Reduced | < 240 | Inflammation, malnutrition, nephrotic syndrome, liver disease, iron overload |
What TIBC measures
Total iron binding capacity measures how much iron the transferrin in a sample could carry if every binding site were occupied. Since transferrin supplies almost all of that capacity, TIBC is in practice an indirect assay of transferrin concentration, and the two move together.
The direction of change is what makes TIBC useful. The liver increases transferrin synthesis when iron stores fall, so TIBC rises in iron deficiency — the opposite direction to serum iron, which is what makes transferrin saturation such a sensitive discriminator. In inflammation transferrin behaves as a negative acute-phase reactant and TIBC falls, which is why anaemia of inflammation shows a low iron with a low or normal TIBC rather than the raised TIBC of true deficiency.
Beyond iron status, TIBC drops whenever transferrin is lost or under-produced: nephrotic syndrome, protein-losing enteropathy, chronic liver disease and malnutrition all lower it. Oestrogen raises it, so pregnancy and combined oral contraceptives produce values above the usual adult range without any iron abnormality.
Frequently asked questions
What is the difference between TIBC and transferrin?
They measure the same thing by different routes. Transferrin is assayed directly as a protein concentration in mg/dL or g/L; TIBC measures the iron-binding capacity that transferrin provides, in µg/dL. As a rough conversion, TIBC in µg/dL is about 1.25 times transferrin in mg/dL.
Why is TIBC high in iron deficiency?
Falling iron stores signal the liver to make more transferrin, increasing the total binding capacity in circulation. Combined with a low serum iron this produces the very low transferrin saturation that characterises iron deficiency.
How do I convert TIBC to µmol/L?
Multiply the µg/dL value by 0.1791, the same factor used for serum iron, because TIBC is expressed in terms of iron-binding capacity rather than protein mass.
Related calculators
References
- Camaschella C. Iron deficiency. Blood. 2019;133(1):30–39.
- Tietz Textbook of Clinical Chemistry and Molecular Diagnostics, iron-binding capacity.
Medical Disclaimer: The tools and content provided here are for educational and reference purposes only. They are not intended to substitute for professional medical advice, diagnosis, or treatment. Clinical decisions should always be based on the comprehensive assessment of a qualified healthcare professional.