Pg E2 Ratio
Calculate your progesterone-to-estradiol (Pg/E2) ratio from hormone blood test results. Free fertility hormone balance assessment tool with ratio interpretation, charts, and clinical reference ranges.
About This Calculator
The Pg E2 Ratio (progesterone-to-estradiol) calculator helps assess female hormonal balance by comparing two key sex hormones: progesterone (Pg) and estradiol (E2). This ratio is a valuable diagnostic tool used by healthcare providers to evaluate hormonal health, fertility potential, and menstrual cycle function. The ratio is particularly relevant during the luteal phase of the menstrual cycle when progesterone levels peak after ovulation.
Estradiol (E2) is the most potent form of estrogen and plays a crucial role in regulating the menstrual cycle, supporting endometrial growth, and maintaining bone density. Progesterone is essential for preparing the uterine lining for implantation, maintaining early pregnancy, and counterbalancing estrogen's proliferative effects. The balance between these two hormones is critical for reproductive health and overall well-being.
The Pg/E2 ratio is calculated using the formula: Pg/E2 Ratio = (Progesterone in ng/mL / Estradiol in pg/mL) × 1000. The multiplication by 1000 accounts for the different units (ng/mL vs pg/mL; 1 ng = 1000 pg). In healthy women during the luteal phase, progesterone-to-estradiol ratio should be between 100 and 500. A ratio below 100 indicates estrogen dominance, while a ratio above 500 indicates progesterone dominance. Clinical interpretation should always consider the phase of the menstrual cycle and individual patient factors.
Who should use this calculator? Women tracking their hormone levels for fertility monitoring, those undergoing IVF or other assisted reproductive treatments, individuals with symptoms of hormonal imbalance (PMS, irregular periods, mood changes), and anyone who has received hormone blood test results and wants to understand their progesterone-to-estradiol balance.
Regional Notes: Hormone level reference ranges may vary between laboratories across India, the US, and the UK. In India, typical estradiol reference ranges in the luteal phase are 70–600 pmol/L (19–160 pg/mL). In the US, lab ranges typically use pg/mL for estradiol and ng/mL for progesterone. In the UK, results are often reported in SI units (pmol/L for estradiol and nmol/L for progesterone). This calculator accepts values in ng/mL (progesterone) and pg/mL (estradiol), which are the most commonly used units in clinical practice worldwide.
Clinical context: The progesterone-to-estradiol ratio gained clinical significance through research by Elgindy et al. (2011, Fertility and Sterility) which identified detrimental cutoff levels for progesterone on the day of hCG administration during IVF cycles. A progesterone level above 1.5 ng/mL on hCG trigger day was associated with lower pregnancy rates. The Pg/E2 ratio is also used to assess hormonal dominance patterns and guide hormone replacement therapy decisions.
Frequently Asked Questions
What is the Pg/E2 ratio (progesterone to estradiol ratio)?
The Pg/E2 ratio (progesterone-to-estradiol ratio) compares the levels of progesterone and estradiol (E2) in your blood. It is an important marker used to assess female hormonal balance, particularly during the luteal phase of the menstrual cycle. The ratio is calculated by dividing the progesterone level by the estradiol level and multiplying by 1000 to express both in the same unit. A balanced ratio typically falls between 100 and 500.
What is a normal progesterone to estradiol ratio?
A normal progesterone-to-estradiol (Pg/E2) ratio in healthy women during the luteal phase falls between 100 and 500. Values below 100 suggest estrogen dominance, while values above 500 suggest progesterone dominance. These ranges are based on progesterone measured in ng/mL and estradiol in pg/mL, with normal luteal phase progesterone levels of 11–29 ng/mL and estradiol levels of 19–160 pg/mL.
What does a low Pg/E2 ratio mean?
A low Pg/E2 ratio (below 100) indicates estrogen dominance, where estrogen levels are relatively high compared to progesterone. This hormonal imbalance has been associated with conditions such as endometriosis, uterine fibroids, breast tenderness, heavy menstrual bleeding, polycystic ovary syndrome (PCOS), and certain estrogen-sensitive cancers. Women with estrogen dominance may experience PMS, mood swings, weight gain, and fatigue. Consult a healthcare provider for evaluation.
What does a high Pg/E2 ratio mean?
A high Pg/E2 ratio (above 500) indicates progesterone dominance, where progesterone levels are relatively high compared to estrogen. This can occur naturally during pregnancy, in the mid-luteal phase, or as a result of progesterone supplementation or hormone therapy. Symptoms may include bloating, breast tenderness, mood changes, fatigue, and depression. In the context of IVF treatment, an elevated progesterone level on the day of hCG administration may negatively impact implantation success.
How is the progesterone to estradiol ratio used in IVF treatment?
The progesterone-to-estradiol ratio is used in IVF treatment to assess endometrial receptivity and predict implantation success. Research by Elgindy et al. (2011) established that a progesterone level above 1.5 ng/mL and a Pg/E2 ratio above a certain threshold on the day of hCG administration may negatively affect pregnancy outcomes. However, some studies suggest a high estradiol/progesterone ratio on the day of ovulation induction predicts successful intracytoplasmic sperm injection (ICSI). IVF protocols vary by clinic and region.
What are normal progesterone and estradiol levels in the luteal phase?
During the luteal phase of the menstrual cycle (days 15–28), normal progesterone levels range from 11 to 29 ng/mL (35–92 nmol/L) and normal estradiol levels range from 19 to 160 pg/mL (70–600 pmol/L). These reference ranges may vary between laboratories in India, the US, and the UK. Results should always be interpreted by a qualified healthcare provider. For unit conversion: 1 ng/mL progesterone = 3.180547 nmol/L; 1 pg/mL estradiol = 3.6713 pmol/L.
Can I rely on this calculator for medical diagnosis?
No. This calculator is for educational and reference purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Hormone levels vary significantly throughout the menstrual cycle, by age, and between individuals. Always consult a qualified healthcare provider — such as an endocrinologist, gynecologist, or fertility specialist — to interpret your hormone test results in the context of your overall health and medical history.
What unit conversions are needed for Pg/E2 ratio calculation?
This calculator expects progesterone in ng/mL and estradiol in pg/mL. To convert from other units: for progesterone, 1 ng/mL = 3.180547 nmol/L (to convert nmol/L to ng/mL, divide by 3.180547). For estradiol, 1 pg/mL = 3.6713 pmol/L (to convert pmol/L to pg/mL, divide by 3.6713). To convert between ng/mL and pg/mL, simply multiply or divide by 1000 since 1 ng/mL = 1000 pg/mL. Most lab reports provide progesterone in ng/mL and estradiol in pg/mL.