What is a normal transferrin saturation?

The generally accepted normal range is 20–50%. Some labs use 15–50%. Values below 20% are often associated with iron deficiency, and values above 50% raise concern for iron overload.

What does low transferrin saturation mean?

A TSAT below 20% suggests either true iron deficiency (low total body iron, often with low ferritin) or functional iron deficiency (adequate stores but impaired release, as in anemia of chronic disease or CKD). Context from ferritin, CBC, and clinical findings is needed.

What does high transferrin saturation mean?

A TSAT above 50% is seen in hereditary hemochromatosis, secondary iron overload (repeated transfusions, excessive supplementation), hemolytic anemia, and liver disease. A fasting TSAT >45% in two separate tests warrants genetic testing for HFE mutations.

What is the difference between TIBC and transferrin?

TIBC is the total capacity of transferrin to bind iron, measured indirectly in mcg/dL. It correlates inversely with ferritin — TIBC rises in iron deficiency and falls in iron overload. Some labs report transferrin directly in mg/dL; TIBC (mcg/dL) ≈ transferrin (mg/dL) × 1.41.

Is this tool a substitute for clinical judgment?

No. This calculator is for educational and reference use only. Lab values must be interpreted alongside clinical history, symptoms, ferritin, CBC, and other relevant tests by a qualified healthcare professional.

Iron Saturation Calculator

Enter serum iron and TIBC to calculate transferrin saturation percentage and interpret for iron deficiency or iron overload.

Iron Panel Values

Serum iron and TIBC in mcg/dL

Serum Iron 60–170 mcg/dL (normal)

TIBC (Total Iron-Binding Capacity) 250–370 mcg/dL (normal)

Results

Enter serum iron and TIBC, then click Calculate

Transferrin Saturation Reference

TSAT Range	Classification	Common Associations
< 10%	Severely low	Severe iron-deficiency anemia, inadequate iron stores
10–20%	Low	Iron deficiency or functional iron deficiency (anemia of chronic disease)
20–50%	Normal	Adequate iron transport; normal iron metabolism
50–60%	Borderline high	Early iron overload, consider fasting retest and ferritin
> 60%	High — iron overload	Hereditary hemochromatosis, secondary overload, liver disease, hemolytic anemia

This tool is for educational and reference purposes only. Always consult a qualified clinician for medical decisions.

Summary

Transferrin saturation (TSAT) is the ratio of serum iron to total iron-binding capacity (TIBC), expressed as a percentage. It reflects how much of the available iron-transport protein (transferrin) is actually carrying iron. Normal TSAT is 20–50%. Values below 20% suggest iron deficiency or functional iron deficiency (as seen in anemia of chronic disease). Values above 50% suggest iron overload conditions such as hereditary hemochromatosis or secondary iron overload.

How it works

Enter your serum iron level in mcg/dL (micrograms per deciliter).
Enter your total iron-binding capacity (TIBC) in mcg/dL.
The calculator divides serum iron by TIBC and multiplies by 100 to get TSAT %.
The result is classified as low, normal, or high with a clinical interpretation.
Reference ranges and common diagnoses associated with each category are displayed below.

Use cases

Evaluating iron-deficiency anemia alongside ferritin and CBC results.
Screening for hereditary hemochromatosis in at-risk patients.
Monitoring iron replacement therapy response.
Distinguishing true iron deficiency from anemia of chronic disease.
Medical student study aid for iron metabolism and lab interpretation.
Quick bedside reference when reviewing iron panel results.

Frequently Asked Questions

Last updated: 2026-06-18 · Reviewed by Nham Vu