Transferrin from TIBC Calculator
Transferrin from TIBC Calculator
Estimate transferrin concentration from a reported TIBC, for guidelines and drug labels written in terms of transferrin.
Transferrin from TIBC
TIBC → transferrinTIBC 330 µg/dL
Formula
Transferrin (g/L) = Transferrin (mg/dL) ÷ 100
- 1.25
- the same stoichiometric factor used in the forward conversion
Worked example
TIBC 330 µg/dL
330 ÷ 1.25 = 264 mg/dL
= 2.64 g/L
Equivalent values
| TIBC µg/dL | Transferrin mg/dL | Transferrin g/L |
|---|---|---|
| 250 | 200 | 2.00 |
| 330 | 264 | 2.64 |
| 400 | 320 | 3.20 |
| 450 | 360 | 3.60 |
When the conversion matters
A number of clinical documents are written in terms of transferrin rather than TIBC. Carbohydrate-deficient transferrin reporting, some nutritional assessment protocols and several European guidelines all quote transferrin in g/L, while many laboratories — particularly in the United States — report only TIBC. Converting lets a result be read against the criterion as written.
The arithmetic simply reverses the stoichiometric relationship: divide TIBC in µg/dL by 1.25 to obtain transferrin in mg/dL, then divide by 100 for g/L. As with the forward conversion, this is an approximation. A small fraction of plasma iron-binding capacity does not come from transferrin, and the two assays are calibrated independently.
Use the estimate for interpretation and for reading against a published threshold. Where transferrin itself is the analyte of interest — assessing hepatic synthetic function, or a nutritional protocol that specifies it — ask the laboratory for a direct measurement instead.
One further point is worth remembering when comparing a converted value against a range. Transferrin reference intervals are strongly affected by oestrogen and by pregnancy, both of which raise the protein well above the standard adult range without implying anything about iron status. A converted value of 400 mg/dL in the third trimester is expected rather than abnormal, and should be read against a pregnancy-specific interval.
Frequently asked questions
How accurate is this conversion?
Usually within about 10% of a directly measured transferrin. It is adequate for interpretation but not for a decision that hinges on a precise value.
How do I get g/L from the result?
Divide the mg/dL result by 100. A transferrin of 264 mg/dL is 2.64 g/L.
Which should I ask the laboratory for?
Whichever your guideline is written in. If you need transferrin saturation, ask for serum iron and TIBC together on the same sample.
Related calculators
References
- Tietz Textbook of Clinical Chemistry and Molecular Diagnostics, transferrin and iron-binding capacity.
- UniProt P02787 — serotransferrin.