If the same person measures his Free T level with two different lab tests, he will get two different levels even after unit conversion, so they are not comparable. The only thing you can compare to is the normal range for the corresponding test.
Total testosterone levels are pretty much independent of the test and can be compared, although the lab normal ranges will differ due to different statistical definitions of 'normal'.
Total testosterone levels are pretty much independent of the test and can be compared, although the lab normal ranges will differ due to different statistical definitions of 'normal'.