Enter the levels of thyroxine and triiodothyronine into the calculator to determine the TSH level. This calculator can also evaluate any of the variables given the others are known.

Tsh Formula

The following formula is used to calculate the TSH (Thyroid Stimulating Hormone) level.

TSH = (T4 * T3) / (T4 + T3)


  • TSH is the Thyroid Stimulating Hormone level (mIU/L) T4 is the level of thyroxine in the blood (ng/dL) T3 is the level of triiodothyronine in the blood (ng/dL)

To calculate the TSH level, multiply the level of thyroxine by the level of triiodothyronine. Then, add the level of thyroxine to the level of triiodothyronine. Divide the first result by the second result to get the TSH level.

What is a Tsh?

A TSH, or Thyroid-Stimulating Hormone, is a hormone produced by the pituitary gland in the brain. It plays a crucial role in regulating the function of the thyroid gland, which is responsible for controlling the body’s metabolism. A TSH test is often used to diagnose thyroid disorders, such as hypothyroidism or hyperthyroidism, by measuring the level of TSH in the blood.

How to Calculate Tsh?

The following steps outline how to calculate the TSH using the given formula:

  1. First, determine the value of T4 (Level of thyroxine in the blood) in ng/dL.
  2. Next, determine the value of T3 (Level of triiodothyronine in the blood) in ng/dL.
  3. Next, use the formula TSH = (T4 * T3) / (T4 + T3) to calculate the TSH level in mIU/L.
  4. Finally, calculate the TSH level using the obtained values of T4 and T3.
  5. After inserting the values and calculating the result, check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge:

T4 (Level of thyroxine in the blood) = 2.5 ng/dL

T3 (Level of triiodothyronine in the blood) = 1.8 ng/dL