Before comparing two testosterone results, check the units printed beside each number. A result in ng/dL cannot be compared directly with one in nmol/L.
The conversion
For testosterone:
- ng/dL to nmol/L: multiply by 0.03467.
- nmol/L to ng/dL: multiply by 28.84.
The factors are rounded, so converting a value back and forth may produce a small rounding difference.
| Original result | Converted result |
|---|---|
| 300 ng/dL | 10.4 nmol/L |
| 500 ng/dL | 17.3 nmol/L |
| 1,000 ng/dL | 34.7 nmol/L |
| 15 nmol/L | 433 ng/dL |
| 25 nmol/L | 721 ng/dL |
These are calculation examples, not treatment targets or reference ranges.
Keep the original result
When recording a test, keep its date, original value, unit, and the reference range supplied by the lab. Conversion changes the unit; it does not establish whether a result is appropriate for you.
Check the marker name as well. Do not substitute a total testosterone result for free testosterone, or use a testosterone conversion factor for a different hormone.
Use the calculator
The free TRT blood test unit converter handles the calculation. Choose the marker and units, then enter the value from your report.
Check the input before using the answer. A calculator can apply the correct formula to a mistyped number.