Nelson posted the table below for test thresholds - very helpful as a general rule of thumb. The values for total test makes sense to me - it seems the range is typically around 300-1200 (although i realize that there are some variance). However, I'm confused by the Free Test values - they seem rather high. For example, the range for my bw from Labcorp is 6.8 to 21.5. Is this just specific to my bloodwork/lab? If different labs have different values then how would one interpret the thresholds provided by these different organizations?