Testosterone Converter
Enter your total testosterone in the unit your lab used. US labs report ng/dL; the UK, Canada, Australia and most of Europe report nmol/L, so 450 on one report and 15.6 on another are the same level.
Educational tool, not a diagnosis. It converts total testosterone. A single result does not establish low testosterone: guidelines ask for two early-morning measurements (the Endocrine Society specifies fasting) plus symptoms, and the free fraction (which depends on SHBG) can tell a different story — the free testosterone calculator handles that. Interpret with the range on your own report and with your clinician.
The conversion, in one line
To go from nmol/L to ng/dL, multiply by 28.84. To go from ng/dL to nmol/L, divide by 28.84 (or multiply by 0.0347). The factor is fixed: one mole of testosterone weighs 288.4 grams, so a count of molecules and a weight of them are locked together. If you need it in your head, dividing ng/dL by 29 gets you within about half a percent (450 ng/dL comes out at 15.5 instead of 15.6).
ng/dL to nmol/L: the reference table
The right-hand column is for adult men and uses two published lines: the CDC-harmonized reference range of 264 to 916 ng/dL, derived from healthy non-obese men aged 19 to 39 and recommended by the Endocrine Society, and the 300 ng/dL cut-off the American Urological Association uses to define low testosterone.
| Testosterone in ng/dL | Same level in nmol/L | Where that sits (men) |
|---|---|---|
| 200 ng/dL | 6.9 nmol/L | Below the harmonized range |
| 250 ng/dL | 8.7 nmol/L | Below the harmonized range |
| 264 ng/dL | 9.2 nmol/L | Harmonized lower limit |
| 300 ng/dL | 10.4 nmol/L | AUA low-testosterone cut-off |
| 350 ng/dL | 12.1 nmol/L | Within the reference range |
| 400 ng/dL | 13.9 nmol/L | Within the reference range |
| 450 ng/dL | 15.6 nmol/L | Within the reference range |
| 500 ng/dL | 17.3 nmol/L | Within the reference range |
| 600 ng/dL | 20.8 nmol/L | Within the reference range |
| 700 ng/dL | 24.3 nmol/L | Within the reference range |
| 800 ng/dL | 27.7 nmol/L | Within the reference range |
| 916 ng/dL | 31.8 nmol/L | Harmonized upper limit |
| 1,000 ng/dL | 34.7 nmol/L | Above the reference range |
nmol/L to ng/dL: the same table in reverse
For results from labs in the UK, Canada, Australia or most of Europe, read against articles and guidelines that quote ng/dL.
| Testosterone in nmol/L | Same level in ng/dL | Where that sits (men) |
|---|---|---|
| 5 nmol/L | 144 ng/dL | Below the harmonized range |
| 8 nmol/L | 231 ng/dL | Below the harmonized range |
| 10 nmol/L | 288 ng/dL | Borderline |
| 12 nmol/L | 346 ng/dL | Within the reference range |
| 15 nmol/L | 433 ng/dL | Within the reference range |
| 20 nmol/L | 577 ng/dL | Within the reference range |
| 25 nmol/L | 721 ng/dL | Within the reference range |
| 30 nmol/L | 865 ng/dL | Within the reference range |
| 35 nmol/L | 1,009 ng/dL | Above the reference range |
Total, free and bioavailable: three different numbers
Most reports give total testosterone, which is what this converter handles. Most of it is bound to SHBG and albumin; only about 2 percent circulates free. When SHBG is high, a normal-looking total can hide a low free fraction, and when SHBG is low the opposite happens. That is why the free testosterone calculator asks for SHBG and albumin as well, and why the free fraction is worth checking before reading too much into a single total.
Bioavailable testosterone is the free fraction plus the part loosely bound to albumin, which can still reach tissues; routine panels rarely report it, but the free testosterone calculator estimates it.
Free testosterone comes in smaller units: 1 ng/dL is 10 pg/mL, and 1 pg/mL is 3.467 pmol/L. So a free testosterone of 9 ng/dL is 90 pg/mL, or about 312 pmol/L.
Before you read anything into one number
Testosterone peaks in the morning and is measurably lower by late afternoon, especially in younger men, and it falls with poor sleep, acute illness, heavy training blocks and weight gain. Both the Endocrine Society and the American Urological Association ask for at least two early-morning measurements, along with symptoms, before calling testosterone low. What a level around 400 means in practice is covered in testosterone at 400 ng/dL, and how ranges shift with age in testosterone levels by age.
Frequently asked questions
- How do you convert testosterone from ng/dL to nmol/L?
- Divide by 28.84, or multiply by 0.0347. A total testosterone of 450 ng/dL is 15.6 nmol/L, and 300 ng/dL is 10.4 nmol/L. The factor is exact because it comes from the molar mass of testosterone, 288.4 grams per mole.
- How do you convert testosterone from nmol/L to ng/dL?
- Multiply by 28.84. A result of 10 nmol/L is 288 ng/dL, 15 nmol/L is 433 ng/dL and 20 nmol/L is 577 ng/dL. Labs in the UK, Canada, Australia and most of Europe report nmol/L, US labs report ng/dL.
- What is 450 ng/dL of testosterone in nmol/L?
- 15.6 nmol/L. For an adult man that sits in the middle of the CDC-harmonized reference range of 264 to 916 ng/dL (9.2 to 31.8 nmol/L) and above the 300 ng/dL cut-off the American Urological Association uses to define low testosterone.
- What testosterone level is considered low in nmol/L?
- The Endocrine Society recommends the harmonized lower limit of 264 ng/dL, which is 9.2 nmol/L, and the American Urological Association uses 300 ng/dL, which is 10.4 nmol/L. Both bodies require two morning measurements and symptoms before calling testosterone low, so one number is not a diagnosis.
- How do you convert free testosterone units?
- Free testosterone is reported in much smaller units. 1 ng/dL is 10 pg/mL, and 1 pg/mL is 3.467 pmol/L, so a free testosterone of 9 ng/dL is 90 pg/mL or 312 pmol/L. If your report only gives total testosterone, the free fraction can be estimated from total testosterone, SHBG and albumin.
- Does Merios store these numbers?
- No. The converter runs entirely in your browser. Your inputs never leave your device and are not sent to a server.
Track this in Merios
Two reports, two units, one testosterone curve.
Merios reads the units off each report you upload and keeps every marker on one scale, so a result in nmol/L and one in ng/dL sit on the same line, next to your sleep and training data from Apple Health.
References: Travison TG, Vesper HW, Orwoll E, et al. Harmonized reference ranges for circulating testosterone levels in men of four cohort studies in the United States and Europe. J Clin Endocrinol Metab 2017;102(4):1161-1173. · Bhasin S, Brito JP, Cunningham GR, et al. Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab 2018;103(5):1715-1744. · Mulhall JP, Trost LW, Brannigan RE, et al. Evaluation and management of testosterone deficiency: AUA guideline. J Urol 2018;200(2):423-432. · Educational tool, not a diagnosis; interpret any result with the reference range printed on your own report and with your physician.