NOTE: we discovered it’s not necessary to do the ratio anymore. We get what we need just by seeing the single number lab result for RT3. A good result is the bottom two numbers of the provided range you get with the RT3 test. So if a range starts at 8, the bottom two numbers are 8 and 9. Occasionally the third from the bottom is fine (if a range starts with 8, the third from the bottom is 10)….of any range your facility uses. We’ve even seen below range which seems to be no problem. 

BEFORE USING THIS BETA CALCULATOR, READ ALL THREE BELOW–they are important:

1) You need to put your “free T3” (or total T3) in the box above FIRST, then put your RT3 result second, for this to work correctly. Then your ratio will show up right above–don’t miss it! It’s small.

2) If your FT3 is above the range (i.e. if you are pooling), you may have a better-looking ratio than you really have if you weren’t pooling. (Pooling means having T3 build high in the blood because it’s not getting to your cells—usually due to low cortisol, high cortisol, or low iron)

3) IF BOTH OF YOUR MEASUREMENTS ARE pg/mL:  you may get a double or triple digit number, and that means it’s missing a decimal. For example, 83 may be 8.3. 

4) IF pg/mL on top and ug/L on bottom, and one is a decimal and the other a whole number...won’t work. 

To understand your result, go back to here to learn why it’s happening and what to do about it.

Why am I trying to find my ratio?

We heard about the ratio from a doctor and where it should fall. It’s okay if you want to do it. But it’s not necessary anymore. You can read about the RT3 problem here.

Are there situations where I can’t go by the RT3 result by itself?

Some literature states the single number RT3 result may “look” normal, but may not be in relation to the Free T3. But we have found that just the result tells the story.

What result am I looking for if I do the ratio?

With the “free T3″/RT3 ratio, healthy ratios will be 20 or higher. With a “total T3″/RT3 ratio, you are looking for 10 or higher.

Your two lab results can come in different units of measure, making it hard for the “math-challenged” to know how to convert the measurements into the same units in order to find the ratio. See below about conversion to the same units.

Does high Free T3 due to pooling cause any problems with the ratio?

Yes. You may have a better-looking ratio than you really have if you weren’t pooling. (Pooling means having T3 build high in the blood because it’s not getting to your cells—usually due to low cortisol, high cortisol, or low iron)

Is there a calculator I can use just to change from one unit of measurement to another?

Yes, try this one: http://www.mens-hormonal-health.com/hormone-unit-conversion-calculator.html   This is not going to give you your RT3 ratio, but it can give you a measurement to put in the down-arrow above in case your particular measurement isn’t shown above.

What can I do if have a ratio that points to an RT3 problem?

This page will explain.

NOTE: this is a BETA calculator. If something didn’t come out right, let my brainy techs and I know.  Email Janie via the Contact Me below with your comments.

Important note: STTM is an information-only site based on what many patients worldwide have reported in their treatment and wisdom over the years. This is not to be taken as personal medical advice, nor to replace a relationship with your doctor. By reading this information-only website, you take full responsibility for what you choose to do with this website's information or outcomes. See the Disclaimer and Terms of Use.