Free tool
Hormone unit converter: nmol/L to ng/dL, pmol/L to pg/mL
Convert testosterone, oestradiol, DHT, prolactin and other blood results between the SI units UK laboratories use and the conventional units on US reports. Pick a test, type in either box, and the factor is shown.
1 nmol/L = 28.84 ng/dL.
- Testosterone
- nmol/L × 28.84 = ng/dL. ng/dL ÷ 28.84 = nmol/L.
- Oestradiol
- pmol/L ÷ 3.671 = pg/mL. pg/mL × 3.671 = pmol/L.
- Free testosterone
- 1 nmol/L = 1,000 pmol/L = 288.4 pg/mL.
- LH, FSH, SHBG
- No change: 1 IU/L = 1 mIU/mL, and SHBG is nmol/L in both.
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Common testosterone values
| nmol/L (UK) | ng/dL (US) | Where it sits in UK guidance |
|---|---|---|
| 8 | 231 | Clearly low; the bottom of the BSSM's 8 to 14 nmol/L trial band |
| 12 | 346 | The BSSM's line: below it, with symptoms, usually needs treatment |
| 15 | 433 | Within the usual adult range |
| 20 | 577 | Within the usual adult range |
| 30 | 865 | Near the top of a harmonised range for young men (31.8 nmol/L) |
Oestradiol for comparison: 100 pmol/L is 27.2 pg/mL, and 150 pmol/L is 40.9 pg/mL.
Every conversion factor
| Test | UK (SI) unit | US unit | SI to US |
|---|---|---|---|
| Testosterone (total) | nmol/L | ng/dL | × 28.84 |
| Free testosterone | pmol/L | pg/mL | ÷ 3.467 |
| Oestradiol (estradiol, E2) | pmol/L | pg/mL | ÷ 3.671 |
| Dihydrotestosterone (DHT) | nmol/L | ng/dL | × 29.04 |
| SHBG | nmol/L | nmol/L | Same number |
| LH | IU/L | mIU/mL | Same number |
| FSH | IU/L | mIU/mL | Same number |
| Prolactin | mIU/L | ng/mL | ÷ 21.2 |
| Progesterone | nmol/L | ng/mL | ÷ 3.18 |
| DHEA sulphate | µmol/L | µg/dL | × 36.85 |
| Cortisol | nmol/L | µg/dL | ÷ 27.59 |
| Haematocrit | L/L | % | × 100 |
| Haemoglobin | g/L | g/dL | ÷ 10 |
| Cholesterol (total, HDL or LDL) | mmol/L | mg/dL | × 38.67 |
| Triglycerides | mmol/L | mg/dL | × 88.57 |
| Glucose | mmol/L | mg/dL | × 18.02 |
| HbA1c | mmol/mol | % | % = 0.0915 × mmol/mol + 2.15 |
| Creatinine | µmol/L | mg/dL | ÷ 88.42 |
| Albumin | g/L | g/dL | ÷ 10 |
Factors come from each molecule’s molar mass (testosterone 288.4 g/mol, oestradiol 272.4 g/mol, DHT 290.4 g/mol) and the published conversions below. To turn total testosterone and SHBG into free testosterone, use the free testosterone calculator.
Questions
How do I convert testosterone from nmol/L to ng/dL?
Multiply by 28.84. For example, 12 nmol/L is 346 ng/dL and 20 nmol/L is 577 ng/dL. To go the other way, divide ng/dL by 28.84.
How do I convert oestradiol from pmol/L to pg/mL?
Divide by 3.671. For example, 100 pmol/L is 27.2 pg/mL. To go from pg/mL to pmol/L, multiply by 3.671.
Why do UK and US blood tests use different units?
UK laboratories report most results in SI units, which count molecules (nmol/L, pmol/L). US laboratories often use conventional units, which weigh them (ng/dL, pg/mL). The factor between the two comes from the molecule's molar mass, so each hormone has its own factor.
Does converting the units change the reference range?
No. Convert the range the same way as the result. But reference ranges differ between laboratories and assays, so compare your result with the range printed on your own report.
Why can't LH and FSH be converted?
They can, but the number doesn't change: 1 IU/L is exactly 1 mIU/mL. SHBG is also reported in nmol/L in both countries.
Is prolactin conversion exact?
Not quite. Prolactin is measured against an international standard, and the usual factor of 21.2 mIU/L per ng/mL applies to the WHO 3rd International Standard. Some assays use a slightly different factor.
Sources
- Hackett G et al. British Society for Sexual Medicine guidelines on adult testosterone deficiency, with statements for practice. World J Mens Health 2023;41:508–37.
- Travison TG et al. Harmonized reference ranges for circulating testosterone levels in men of four cohort studies. J Clin Endocrinol Metab 2017;102:1161–73.
- NGSP. IFCC–NGSP HbA1c master equation.
- PubChem compound records: testosterone, estradiol, dihydrotestosterone.
Keep reading
- Tools
Free testosterone calculator
Free and bioavailable testosterone from total testosterone, SHBG and albumin, using the Vermeulen formula.
- Tools
Testosterone level checker
Place a testosterone result against UK thresholds and a harmonised adult range, with what changes with age.
- Guides
Blood tests for steroid users
What to test, when, and where in the UK, from published guidance for people who use anabolic steroids.
For information only, not medical advice. GeneticEdge does not recommend or endorse anabolic steroid use, and no genetic test can tell you whether steroids are safe for you. Talk to a GP or pharmacist about your health. Last reviewed 30 October 2026.