Testosterone to Estradiol Ratio Calculator

By Małgorzata Koperska, MD
Last updated: Dec 02, 2020

The calculation of testosterone to estradiol ratio, also known as T/E2, is a parameter linked to a whole spectrum of male health aspects, primarily associated with sexual functions. The values needed for the estimation are free testosterone (T) and estradiol (E2) concentrations. The calculator can also be used for converting estradiol and testosterone units of measurement.

How is testosterone to estradiol ratio calculated?

The formula itself is very simple:

ratio = testosterone / estradiol

The tricky part is that before the calculation of testosterone to estradiol ratio, both hormone concentrations need to be expressed in the same units, and they're generally presented in different ways: testosterone in ng/dL, and estradiol in pg/mL.

There's no fixed range for the ratio value. It's important that testosterone (10-35 nmol/L or 300-1000 ng/dL) and estradiol levels (50-200 pmol/L or 14-55 pg/mL) are within normal ranges. There is a very interesting article by drs. Moskowic, Eisenberg, and Lipschultz on the topic of T/E2 ratio fluctuations.

What unit is testosterone measured in?

The most frequently used testosterone unit of measurement is ng/dL (nanogram per deciliter), and the international standard is nmol/L (nanomole per liter). The conversion of its concentration is calculated by using this formula:

1 nmol/L = 1000 pmol/L = 28.85 ng/dL


1 ng/dL = 0.03466 nmol/L = 34.66 pmol/L

You could expect the conversion of estradiol units to be conducted in the same way. However, the concentration of every substance is calculated differently. For estradiol, it's done this way:

1 pmol/L = 0.2724 pg/mL


1 pg/mL = 3.6713 pmol/L

Check out our other calculators to see how progesterone, cholesterol, and glucose units are converted.

Małgorzata Koperska, MD