Iron / TIBC (Transferrin Saturation)
Serum iron alone swings a lot within a single day, so it is hard to read on its own. Dividing by TIBC gives a more stable picture of how much of the iron-carrying capacity is actually filled.
Your numbers
Transferrin saturation
27.3%
Serum iron (μg/dL)
90μg/dL
What it means
27.3% is within the normal range (20–50%).
Formula
Transferrin saturation = Serum iron (μg/dL) ÷ TIBC (μg/dL) × 100
This is a reading aid, not a diagnosis. Inflammation and liver disease also move this number, so read it together with ferritin.
What to enter
| Input | Default | Accepted range |
|---|---|---|
| Serum iron (μg/dL) (μg/dL) | 90 | 10 ~ 300 |
| TIBC (μg/dL) (μg/dL) | 330 | 150 ~ 500 |
Step by step
Quick reference table
Results when only Serum iron (μg/dL) (μg/dL) changes and everything else stays put.
| Serum iron (μg/dL) (μg/dL) | Transferrin saturation (%) | Serum iron (μg/dL) (μg/dL) |
|---|---|---|
| 45 | 13.6 | 45 |
| 67.5 | 20.5 | 68 |
| 90 | 27.3 | 90 |
| 135 | 40.9 | 135 |
| 180 | 54.5 | 180 |
What each result means
| Result | At default values |
|---|---|
| Transferrin saturation (%)Serum iron divided by TIBC; shows how much of the iron-carrying capacity is actually in use. | 27.3 |
| Serum iron (μg/dL) (μg/dL) | 90 |
Common mistakes
This is a reading aid, not a diagnosis. Inflammation and liver disease also move this number, so read it together with ferritin.
Frequently asked questions
QHow is Iron / TIBC (Transferrin Saturation) calculated?
Transferrin saturation = Serum iron (μg/dL) ÷ TIBC (μg/dL) × 100 — Serum iron alone swings a lot within a single day, so it is hard to read on its own. Dividing by TIBC gives a more stable picture of how much of the iron-carrying capacity is actually filled.
QCan you walk through an example?
With Serum iron (μg/dL) 90μg/dL, TIBC (μg/dL) 330μg/dL, the answer is Transferrin saturation 27.3%.
QWhat do I need to enter?
Enter Serum iron (μg/dL), TIBC (μg/dL). The result recalculates as you type, and an empty box counts as zero.
QHow much does the answer move if I change a number?
Changing only Serum iron (μg/dL) (μg/dL) moves the answer to Serum iron (μg/dL) (μg/dL) 45 → Transferrin saturation (%) 13.6 and Serum iron (μg/dL) (μg/dL) 180 → Transferrin saturation (%) 54.5. The table below lays out five steps.
QHow are the numbers rounded?
Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.
QAnything to watch out for?
This is a reading aid, not a diagnosis. Inflammation and liver disease also move this number, so read it together with ferritin.
Related calculators
These calculators help you understand health figures; they do not replace diagnosis or prescription. See a clinician if you have symptoms.