mg/dL to mmol/L Converter
Convert glucose, cholesterol, triglycerides and more between mg/dL and mmol/L. Each substance has its own factor, and this applies the right one.
Creatinine is reported in µmol/L rather than mmol/L, so it uses its own factor of 88.4.
The factors this tool uses
There is no single number that converts mg/dL to mmol/L. mg/dL measures mass per volume and mmol/L measures the number of molecules per volume, so the conversion depends on how heavy the molecule is. That is why the factors below differ by nearly fiftyfold.
| Substance | mg/dL → mmol/L | mmol/L → mg/dL |
|---|---|---|
| Glucose | ÷ 18.0182 | × 18.0182 |
| Total / LDL / HDL cholesterol | ÷ 38.67 | × 38.67 |
| Triglycerides | ÷ 88.57 | × 88.57 |
| Uric acid | ÷ 59.48 (to mmol/L) | × 59.48 |
| Creatinine | × 88.4 (to µmol/L) | ÷ 88.4 |
The mistake worth avoiding
Applying the glucose factor to a cholesterol result is the single most common error, and it is not a small one. An LDL of 130 mg/dL is 3.4 mmol/L. Divide it by 18 instead and you get 7.2 — a number that looks alarming and means nothing. If you take one thing from this page: check which substance you are converting before you divide.
Familiar landmarks in both units
Handy for sanity-checking a converted result:
- Fasting glucose — 100 mg/dL = 5.6 mmol/L (the impaired-fasting-glucose boundary in many guidelines)
- Fasting glucose — 126 mg/dL = 7.0 mmol/L (the usual diabetes diagnostic threshold)
- LDL cholesterol — 100 mg/dL = 2.6 mmol/L, 70 mg/dL = 1.8 mmol/L
- Triglycerides — 150 mg/dL = 1.7 mmol/L, 200 mg/dL = 2.3 mmol/L
- Non-HDL cholesterol — 130 mg/dL = 3.4 mmol/L
Why this comes up so often
Reference ranges are printed in whatever unit the laboratory uses, and people increasingly hold results from more than one country: a US panel from a work checkup, a European one from a holiday clinic, an old report from before they moved. Comparing those without converting produces conclusions that are simply arithmetic errors — which is a shame, because the comparison across years is the most useful thing you can do with lab results.
Unit mismatches are also why a single number is a weak object to reason about. What actually tells you something is the same marker measured repeatedly, in a consistent unit, over time. That is the part a converter cannot do for you.
Read more
- HbA1c explained: your 3-month blood sugar snapshot
- What your cholesterol numbers actually mean
- How to read blood test results without a medical degree
- HbA1c to average glucose converter
References
- Lipid Conversion Factors. NCBI Bookshelf.
- NGSP. HbA1c and Estimated Average Glucose (eAG).
- National Institute of Diabetes and Digestive and Kidney Diseases. Diabetes Tests & Diagnosis.
This tool is for education and isn't medical advice. Reference ranges vary between laboratories — check the range printed on your own report, and discuss your results with a qualified clinician.
Frequently asked questions
- How do I convert mg/dL to mmol/L?
- Divide by a factor that depends on the substance, because the conversion is based on molecular weight. Glucose: divide mg/dL by 18.0182. Total, LDL and HDL cholesterol: divide by 38.67. Triglycerides: divide by 88.57. There is no single universal factor — using the glucose factor on a cholesterol result gives a badly wrong answer.
- Why do glucose and cholesterol use different conversion factors?
- Because mg/dL measures mass and mmol/L measures the number of molecules. Converting between them requires the molecular weight of the specific substance. Glucose is about 180 g/mol, cholesterol about 387, and triglycerides (as triolein) about 886 — which is why the three factors differ so much.
- Which countries use mmol/L and which use mg/dL?
- The United States reports in mg/dL for glucose and lipids. Most of Europe, the UK, Canada, Australia and China report in mmol/L. This is why the same result can look completely unfamiliar depending on which lab produced it, and why comparing a US report to a European one requires converting first.
- Is a glucose of 100 mg/dL the same as 5.6 mmol/L?
- Yes. 100 divided by 18.0182 gives 5.55 mmol/L, usually reported as 5.6. That value sits right at the boundary where many guidelines begin calling fasting glucose impaired, which is a useful thing to recognise in either unit.
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