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Aldosterone in two units: the short answer
To convert aldosterone from ng/dL to pmol/L, multiply by 27.74. To go back from pmol/L to ng/dL, multiply by 0.03605 (or divide by 27.74). For example, 12 ng/dL × 27.74 = 333 pmol/L. The converter above works in both directions and shows where the result sits against typical reference ranges.
What the test measures
Aldosterone is the adrenal hormone that makes the kidneys retain sodium and lose potassium. US labs report it in ng/dL; UK, European and Australian labs use pmol/L. Aldosterone's molar mass is 360.4 g/mol, so 1 ng/dL = 27.74 pmol/L.
Why the units differ
Screening for primary aldosteronism uses the aldosterone-to-renin ratio, and published cut-offs depend heavily on units. Converting aldosterone correctly is the first step before calculating or comparing a ratio.
Where the factor comes from
The conversion factor comes from the molar mass (360.44 g/mol) and the volume units on each side. Laboratories may round the factor slightly differently, which can change the last digit but never the clinical meaning.
How to convert step by step
- Check the unit printed next to the result on your report – ng/dL or pmol/L.
- ng/dL → pmol/L: multiply by 27.74.
- pmol/L → ng/dL: multiply by 0.03605.
- Round to the same number of decimals your lab uses.
Worked example in reverse: 139.0 pmol/L × 0.03605 = 5.0 ng/dL.
Aldosterone conversion chart
| ng/dL | pmol/L |
|---|---|
| 2 | 55 |
| 4 | 111 |
| 5 | 139 |
| 8 | 222 |
| 10 | 277 |
| 12 | 333 |
| 15 | 416 |
| 20 | 555 |
| 25 | 694 |
| 30 | 832 |
| 40 | 1,110 |
| pmol/L | ng/dL |
|---|---|
| 55 | 2 |
| 111 | 4 |
| 139 | 5 |
| 222 | 8 |
| 277 | 10 |
| 333 | 12 |
| 416 | 15 |
| 555 | 20 |
| 694 | 25 |
| 832 | 30 |
| 1110 | 40 |
Aldosterone levels: what the numbers mean
| Category | ng/dL | pmol/L |
|---|---|---|
| Typical upright, normal-salt dietAbout 111–860 pmol/L; varies by posture, salt intake and lab | 4 – 31 | 111 – 860 |
Aldosterone depends on posture, time of day, sodium and potassium status and many blood-pressure medicines. Use the range on your report.
Aldosterone depends on posture, time of day, sodium and potassium status and many blood-pressure medicines. Use the range on your report.
Interpreting aldosterone results
Primary aldosteronism is one of the most common treatable causes of high blood pressure, especially when blood pressure is hard to control or potassium is low. Before testing, low potassium should be corrected and some medicines (for example spironolactone) may need to be adjusted, because they change aldosterone and renin. A raised ratio is a screening result only; confirmation tests are done by a specialist.
A single result outside the reference range is common and often not significant on its own. Reference ranges are set so that about 1 in 20 healthy people fall outside them, and every laboratory sets its own limits for its method. Use the range printed on your report and discuss results with the clinician who ordered the test.
When to see a doctor
Contact your clinician if a result is flagged as abnormal and you have symptoms, if a value is far outside the range, or if results are changing over time. This page explains units; it cannot diagnose or replace medical advice.
Frequently asked questions
What is 15 ng/dL aldosterone in pmol/L?
15 × 27.74 = 416 pmol/L.
Can I convert the aldosterone-renin ratio with this factor?
Only the aldosterone part. Renin may be reported as activity (ng/mL/h) or concentration (mIU/L or pg/mL), so the ratio's units must be converted separately.
Can I use this converter for any lab?
Yes for the unit conversion, which is fixed by chemistry. Reference ranges differ between labs and methods, so compare your converted value with your own lab's range.