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Zinc in two units: the short answer
To convert zinc from µg/dL to µmol/L, multiply by 0.153. To go back from µmol/L to µg/dL, multiply by 6.536 (or divide by 0.153). For example, 80 µg/dL × 0.153 = 12.2 µmol/L. The converter above works in both directions and shows where the result sits against typical reference ranges.
What the test measures
Serum or plasma zinc is reported in µg/dL in the US and in µmol/L elsewhere. Zinc's atomic mass is 65.38 g/mol, so 1 µg/dL = 0.153 µmol/L and 1 µmol/L = 6.54 µg/dL.
Why the units differ
Zinc deficiency cut-offs from nutrition research are often quoted in µg/dL (for example about 70 µg/dL in fasting morning samples), while European labs report µmol/L.
Where the factor comes from
The conversion factor comes from the molar mass (65.38 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 – µg/dL or µmol/L.
- µg/dL → µmol/L: multiply by 0.153.
- µmol/L → µg/dL: multiply by 6.536.
- Round to the same number of decimals your lab uses.
Worked example in reverse: 9.2 µmol/L × 6.536 = 60.1 µg/dL.
Zinc conversion chart
| µg/dL | µmol/L |
|---|---|
| 40 | 6.1 |
| 50 | 7.7 |
| 60 | 9.2 |
| 70 | 10.7 |
| 80 | 12.2 |
| 90 | 13.8 |
| 100 | 15.3 |
| 120 | 18.4 |
| 150 | 23 |
| µmol/L | µg/dL |
|---|---|
| 6.1 | 39.9 |
| 7.7 | 50.3 |
| 9.2 | 60.1 |
| 10.7 | 69.9 |
| 12.2 | 79.7 |
| 13.8 | 90.2 |
| 15.3 | 100 |
| 18.4 | 120.3 |
| 23 | 150.3 |
Zinc levels: what the numbers mean
| Category | µg/dL | µmol/L |
|---|---|---|
| Low<9.2 µmol/L | < 60 | < 9.2 |
| Typical adult rangeAbout 9.2–18.4 µmol/L; varies by lab | 60 – 120 | 9.2 – 18.4 |
Typical adult interval. Zinc is lower after meals, later in the day, in pregnancy and during inflammation.
Typical adult interval. Zinc is lower after meals, later in the day, in pregnancy and during inflammation.
Interpreting zinc results
Zinc is needed for immunity, wound healing, taste and skin. Low levels are seen with poor intake, gut disease (Crohn's, celiac), bariatric surgery, alcohol use disorder and some diuretics. Too much zinc from long-term high-dose supplements can cause copper deficiency, which is why zinc and copper are sometimes checked together.
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 10 µmol/L zinc in µg/dL?
10 × 6.54 = 65 µg/dL.
Does a low zinc level always mean deficiency?
No. Infection, inflammation, low albumin and non-fasting samples all lower serum zinc. Clinicians interpret it with symptoms and context.
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.