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Transferrin Saturation Calculator

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What is transferrin saturation?Transferrin saturation formulaTransferrin saturation reference valuesInterpretation of saturation valuesFAQs

This transferrin saturation calculator will help to characterize the iron economy of your body. Transferrin is a specialized iron carrier protein present in our blood. Each transferrin molecule can carry up to two iron (Fe³⁺) ions. In this article, you will learn how to use our transferrin saturation calculator to compute and interpret different saturation values.

While analyzing your blood test results, you may also want to calculate your anion gap or RBC indices.

We try our best to make our Omni Calculators as precise and reliable as possible. However, this tool can never replace a professional doctor's assessment. All information on this website is for informational purposes only and is not intended to serve as a substitute for medical consultation. Always consult your results with a health care provider.

What is transferrin saturation?

The percent value calculated here can tell you what fraction of all available transferrin carries chemically bound iron ions. As such, it is an excellent tool for assessing the balance between your body's iron uptake and output. It is often relevant to clinicians as it is a cheap and relatively non-invasive method of monitoring the iron levels in the patient's body.

Transferrin saturation formula

There are two accepted mathematical formulas for the calculation of percentage transferrin saturation:

  1. Saturation = (Fe / TIBC) × 100

  2. Saturation = (Fe / TF) × 70.9

Abbreviations in the above equations are:

  • Fe – Serum iron concentration (in µg/dL);
  • TIBC – Total iron-binding capacity (in µg/dL); and
  • TF – Serum transferrin concentration (mg/dL).

To calculate your transferrin saturation using the second equation, simply expand the Second method section and enter the required values.

An example use of these formulas is demonstrated below:

  1. Saturation = (112 [µg/dL] / 310 [µg/dL]) × 100 = 36.13%

  2. Saturation = (112 [µg/dL] / 219 [mg/dL]) × 70.9 = 36.26%

Transferrin saturation reference values

You can compare your computed transferrin saturation value to the reference ranges listed below:

  • Males: 15-50%; and
  • Females: 12-45%.

Typically in a healthy human, about one-third of all transferrin is saturated with iron ions. This leaves two-thirds of all transferrin binding sites empty as a reserve in the event of increased iron uptake. The reference values differ for children and patients during hemodialysis.

Interpretation of saturation values

Decreased transferrin saturation can be caused by the following:

  • Iron-poor diet (e.g., unbalanced vegan diet);
  • Impaired iron absorption (e.g., celiac disease);
  • Pregnancy and lactation;
  • Hormonal contraceptives; or
  • Chronic blood loss (e.g., colon cancer).

Prolonged effects of the above factors may eventually lead to iron-deficiency anemia.

You can use our hematocrit hemoglobin ratio calculator to keep an eye on your risk of anemia. Moreover, you might be interested in inspecting your absolute reticulocyte count (see absolute reticulocyte count calculator) to control the condition of blood-producing cells in your bone marrow.

Increased transferrin saturation can be caused by:

  • Iron-rich diet;
  • Iron supplements;
  • Increased iron absorption (e.g., primary hemochromatosis); and
  • Repeated blood transfusions.

A saturation value higher than the reference range indicates that you have too much iron in your body. Such a disorder, called iron overload or hemochromatosis, may increase the risk of liver disease and many other conditions.


What is a transferrin?

Transferrin is a protein produced by your liver that is the main carrier of iron in the blood and transports it throughout the body. When you have enough transferrin, your body can efficiently use the iron you get from your diet. When iron levels are low, your body will try to compensate for this by making more transferrin.

What is transferrin saturation in blood test?

The transferrin saturation test tells us how much iron in the blood is bound to transferrin. Normally, your body controls iron levels and tries to prevent them from increasing or decreasing excessively. If you get a low transferrin saturation, this usually indicates an iron deficiency, while a high saturation often confirms an iron overload.

What is the difference between transferrin and TIBC tests?

The transferrin test directly measures the level of this protein in your blood. In contrast, total iron-binding capacity (TIBC) is used to indirectly measure transferrin, where its level is expressed as the amount of iron it is able to bind.

What is the transferrin saturation for a serum iron concentration of 90 μg/dL and transferrin of 310 mg/dL?

20.58%. Use the values of Fe = 90.0 μg/dL and TF = 310 mg/dL in the equation:

(Fe / TF) × 70.9 = (90 μg/dL / 310 mg/dL) × 70.9 = 20.58%.

Note that the calculated result is within the transferrin saturation standard for adults (males: 15-50% and females: 12-45%).

Is iron saturation the same as transferrin saturation?

Yes. The terms transferrin saturation and iron saturation may be used interchangeably; however, the value is now most commonly referred to simply as transferrin saturation. Do not confuse this with another value, iron-binding capacity, which is used when determining a patient's iron status.

How can I increase transferrin saturation?

You can make these lifestyle changes to increase transferrin saturation in your blood:

  1. Favor iron-rich foods.
  2. Reduce the amount of fiber, whole grain products, and chili.
  3. Drink less coffee, cocoa, green tea, and herbal teas.
  4. Try using cast iron cookware as they increase the amount of iron in meals.
  5. Avoid intense endurance exercise to prevent iron levels from dropping too low.
  6. Consult your doctor for other causes of low transferrin levels.

First method

Calculate transferrin saturation using the first equation:

TSAT = (Fe / TIBC) × 100

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