How is testosterone levels measured?

Carefully!: Sorry! i couldn't resist. Testosterone is typically measured by blood test, same as you might do to check for high cholesterol or diabetes. Testosterone levels vary depending upon time of day, highest in morning & lowest in afternoon/evening. Normal reference range depends upon lab & equipment used as well as test ordered. You can also check levels via saliva although this isn't standardized.

Total and Free: Measuring total testosterone is easy. The standard test for free testosterone (that is the part that is available to help you) is notoriously unreliable. The best test for free testosterone is equilibrium dialysis, and it is expensive. Free testosterone can be adequately estimated if you know your total, your sex hormone binding globulin and your Albumin levels.