Lower limit = the beginning of the reference range shown on your lab report

Upper limit = the end of the reference range shown on your lab report

Interpreting the thyroid calculator results

The thyroid mainly produces the hormones fT4 (thyroxine) and fT3 (triiodothyronine). fT4 is a precursor that the body converts into fT3—the active hormone that regulates many metabolic processes..

A good balance between these two hormones is essential for your well-being. Our thyroid value calculator helps you better understand your fT3 and fT4 levels. These values are often given in different units, which can make interpretation difficult. The calculator converts your results into percentages so you can see at a glance whether they’re in the optimal range.

Experience shows that most people only start to feel well when their values are in the upper third (67%–100%).

Thyroid calculator: what you should know

What matters most isn’t just the lab result, but especially how you personally feel.

A low fT3 level can also indicate a conversion issue from fT4 to fT3. With natural thyroid hormones derived from pork, the fT4 level may naturally be lower in relation to fT3.

With our calculator, you’ll gain clarity about your values—so you can make informed decisions for your health.