What is a normal transferrin saturation?

Normal transferrin saturation is generally 20–50 % in adults. Values vary slightly by laboratory and sex — some references cite 15–50 % as the normal range.

What does low transferrin saturation mean?

A TSAT below 20 % (some guidelines use 16 % as the cutoff) typically indicates iron deficiency, which can be due to inadequate dietary intake, poor absorption, chronic blood loss, or increased iron demand.

What does high transferrin saturation mean?

A TSAT above 50–60 % may suggest iron overload. Common causes include hereditary hemochromatosis, excessive iron supplementation, hemolytic anemia, or liver disease. Further evaluation with ferritin and genetic testing is usually recommended.

How is transferrin saturation calculated?

TSAT (%) = (Serum Iron ÷ TIBC) × 100. Both values must be in the same unit. Serum iron and TIBC are typically reported in mcg/dL or µmol/L.

Is transferrin saturation the same as iron saturation?

Yes — "iron saturation," "transferrin saturation," and "TSAT" are used interchangeably in clinical settings. They all refer to the same calculation.

Can I convert between mcg/dL and µmol/L?

Yes. Multiply mcg/dL by 0.1791 to get µmol/L, or multiply µmol/L by 5.583 to get mcg/dL. The TSAT result is unit-independent as long as both values use the same unit.

Transferrin Saturation Calculator

Enter serum iron and total iron-binding capacity (TIBC) to instantly calculate transferrin saturation and interpret iron status.

Enter Lab Values

Provide serum iron and TIBC in the same unit.

Unit System

Serum Iron (mcg/dL)

Total Iron-Binding Capacity (TIBC) (mcg/dL)

Reference Ranges

Low: < 20 % — possible iron deficiency

Normal: 20 – 50 %

High: > 50 % — possible iron overload

Enter values on the left and click Calculate.

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 iron-transport protein transferrin is currently occupied by iron. Normal TSAT ranges from roughly 20–50 %; values below 20 % suggest iron deficiency, while values above 50 % may indicate iron overload conditions such as hereditary hemochromatosis.

How it works

Enter your serum iron value (mcg/dL or µmol/L).
Enter your total iron-binding capacity (TIBC) in the same units.
Select the unit system (mcg/dL or µmol/L).
Click Calculate — the tool divides serum iron by TIBC and multiplies by 100.
Review the result and the color-coded clinical interpretation.

Use cases

Screen for iron deficiency anemia in patients with low hemoglobin.
Monitor iron replacement therapy response over time.
Evaluate for hereditary hemochromatosis when TSAT is elevated.
Assess iron status in chronic kidney disease patients on dialysis.
Supplement complete iron panel interpretation alongside ferritin and serum iron.
Support clinical decision-making before iron supplementation.

Frequently Asked Questions

Last updated: 2026-09-30 · Reviewed by Nham Vu