Estrogen / Progesterone Ratio Calculator
Enter your lab values below. This calculator standardizes units and returns a progesterone-to-estrogen (P:E2) ratio.
Educational use only. Reference ranges vary by lab method, cycle timing, age, medications, and clinical context.
What is an estrogen progesterone ratio?
The estrogen-progesterone relationship is often discussed when reviewing hormone balance. In most practical lab discussions, people are comparing estradiol (E2) and progesterone. Because these hormones are often reported in different units, a simple raw division can be misleading unless you convert values first.
This tool calculates a progesterone-to-estradiol ratio (P:E2) after converting each value to the same base unit (pg/mL). That gives you a cleaner apples-to-apples comparison.
How this calculator works
Step 1: Convert estradiol to pg/mL
- If entered in pg/mL, no change is needed.
- If entered in pmol/L, the calculator multiplies by 0.2724.
Step 2: Convert progesterone to pg/mL
- ng/mL → pg/mL: multiply by 1000
- nmol/L → pg/mL: multiply by 314.47
- pg/mL: no conversion needed
Step 3: Compute ratio
P:E2 ratio = Progesterone (pg/mL) ÷ Estradiol (pg/mL)
Progesterone becomes 12,000 pg/mL, so ratio = 12,000 ÷ 120 = 100:1.
Interpreting your result (general guidance)
Different clinicians use different interpretation frameworks, and serum, saliva, and dried urine tests are not interchangeable. Very broad, non-diagnostic guidance often looks like this:
- Below 50:1 – relatively low progesterone compared with estradiol
- 50:1 to 100:1 – lower-mid relative progesterone range
- 100:1 to 500:1 – often considered a common balanced range in some clinical models
- Above 500:1 – relatively high progesterone compared with estradiol
These are not universal lab cutoffs. They are only rough discussion points.
Timing matters: test day can change everything
Hormones are dynamic. A ratio from one day can differ significantly from another day.
- Regular menstrual cycles: interpretation is usually tied to cycle phase (follicular, ovulatory, luteal).
- Perimenopause: hormone fluctuations can be large from cycle to cycle.
- Postmenopause: absolute values are lower, and symptoms may not map cleanly to ratio alone.
- Hormonal contraception or HRT: medications can strongly affect measured values and ratio meaning.
Use ratio with symptoms and full labs
A useful hormone review usually includes:
- Cycle history and symptom pattern (sleep, mood, bleeding, breast tenderness, headaches)
- Absolute estradiol and progesterone levels, not ratio alone
- Related markers when appropriate (LH, FSH, prolactin, thyroid panel, and sometimes androgens)
- Medication and supplement review
Frequently asked questions
Is a higher ratio always better?
No. Both very low and very high relative ratios can be clinically relevant depending on your context, goals, and symptoms.
Can I diagnose estrogen dominance from this calculator?
No. The term is used differently across medical and functional frameworks. This calculator is best used as a conversation aid, not a diagnosis tool.
Why does unit conversion matter so much?
Because progesterone is often measured in ng/mL while estradiol is commonly in pg/mL. Without conversion, the ratio can be off by orders of magnitude.
Important medical note
This page is for educational purposes only and does not provide medical advice. If you have irregular cycles, severe PMS/PMDD symptoms, infertility concerns, heavy bleeding, or menopausal symptoms, discuss results with a licensed clinician who can interpret your labs in context.