US labs report cholesterol in mg/dL. The UK, Europe, Canada and Australia use mmol/L. To convert cholesterol, divide mg/dL by 38.67 or multiply mmol/L by 38.67. Triglycerides use 88.57 instead.
General information, not medical advice
This tool is for education and doesn't diagnose or treat anything. Lab methods and targets vary, and your own targets depend on your overall heart risk, so go through your results with your doctor or another qualified health professional.
Quick-reference chart
Total, LDL, HDL and non-HDL cholesterol
| mg/dL | = mmol/L | mmol/L | = mg/dL |
|---|---|---|---|
| 40 | 1.03 | 1.0 | 39 |
| 50 | 1.29 | 1.2 | 46 |
| 55 | 1.42 | 1.4 | 54 |
| 60 | 1.55 | 1.8 | 70 |
| 70 | 1.81 | 2.0 | 77 |
| 100 | 2.59 | 2.6 | 101 |
| 115 | 2.97 | 3.0 | 116 |
| 130 | 3.36 | 3.4 | 131 |
| 160 | 4.14 | 4.0 | 155 |
| 190 | 4.91 | 4.5 | 174 |
| 200 | 5.17 | 5.0 | 193 |
| 220 | 5.69 | 5.5 | 213 |
| 240 | 6.21 | 6.0 | 232 |
| 260 | 6.72 | 6.5 | 251 |
| 280 | 7.24 | 7.0 | 271 |
| 300 | 7.76 | 7.5 | 290 |
Triglycerides
| mg/dL | = mmol/L | mmol/L | = mg/dL |
|---|---|---|---|
| 50 | 0.56 | 0.5 | 44 |
| 100 | 1.13 | 1.0 | 89 |
| 150 | 1.69 | 1.5 | 133 |
| 175 | 1.98 | 1.7 | 151 |
| 200 | 2.26 | 2.0 | 177 |
| 300 | 3.39 | 2.3 | 204 |
| 400 | 4.52 | 3.0 | 266 |
| 500 | 5.65 | 4.5 | 399 |
| 800 | 9.03 | 5.6 | 496 |
| 1000 | 11.29 | 10.0 | 886 |
Labs in the UK usually round mmol/L results to one decimal place, so a converted value can differ from your report by 0.1. To see what a number means rather than just its unit, use the ranges chart in how to read your cholesterol test results.
Why the UK and US use different units
The two units measure the same thing in different ways. mg/dL (milligrams per decilitre) is the weight of cholesterol in a tenth of a litre of blood. mmol/L (millimoles per litre) is the number of cholesterol molecules in a litre, counted in millimoles.
mmol/L is the SI (International System of Units) unit for blood tests. From the 1970s onwards, most countries moved their medical labs over to SI units: the UK and Ireland, most of Europe, Canada, Australia and New Zealand all report cholesterol in mmol/L. US labs kept the older "conventional" units, so American guidelines, articles and apps quote mg/dL. Japan and India also commonly use mg/dL.
That's why the same result can look alarming in one country and normal in another. An LDL of "3" is a reasonable result in mmol/L (116 mg/dL), but an LDL of 3 mg/dL is impossible. If a number seems strange, check the unit first.
Where the conversion factors come from
One mole of cholesterol weighs 386.65 g. So 1 mmol/L of cholesterol is 386.65 mg per litre, or 38.67 mg per decilitre. That's where the 38.67 comes from, and it applies to total, LDL, HDL and non-HDL cholesterol because all four measure the cholesterol molecule.
Triglycerides are a mix of molecules, so labs use the weight of a typical one (triolein, about 885.7 g per mole), giving a factor of 88.57. Don't use 38.67 for triglycerides. A triglyceride result of 1.7 mmol/L is 151 mg/dL, not 66.
Sources
- NHS: Cholesterol levels (mmol/L ranges used in the UK)
- MedlinePlus: Cholesterol levels, what you need to know (mg/dL ranges used in the US)
- PubChem: Cholesterol (molar mass, the basis of the 38.67 factor)
- BIPM: The International System of Units (SI)
Frequently asked questions
How do I convert cholesterol from mg/dL to mmol/L?
Divide by 38.67. For example, a total cholesterol of 200 mg/dL ÷ 38.67 = 5.2 mmol/L. The same factor works for total, LDL, HDL and non-HDL cholesterol.
How do I convert cholesterol from mmol/L to mg/dL?
Multiply by 38.67. An LDL of 3.0 mmol/L × 38.67 = 116 mg/dL. For triglycerides, multiply by 88.57 instead: 1.7 mmol/L × 88.57 = 151 mg/dL.
Why are triglycerides converted with a different number?
mmol/L counts molecules, while mg/dL weighs them. A triglyceride molecule is a little over twice as heavy as a cholesterol molecule, so the factor is bigger: 88.57 for triglycerides against 38.67 for cholesterol. Using the cholesterol factor on triglycerides gives an answer less than half the true value.
What is 5.2 mmol/L cholesterol in mg/dL?
About 201 mg/dL (5.2 × 38.67). That sits right at the US "desirable" cut-off of 200 mg/dL for total cholesterol, and just above the NHS guide of 5 mmol/L.
Is a cholesterol level of 6 mmol/L high?
A total cholesterol of 6.0 mmol/L is about 232 mg/dL. That is above the NHS guide of 5 mmol/L and in the US "borderline high" range (200–239 mg/dL). The breakdown matters more than the total, so check your non-HDL and LDL. Our guide to reading cholesterol results goes through each number.
What is an LDL of 100 mg/dL in mmol/L?
About 2.6 mmol/L. Other common LDL cut-offs: 70 mg/dL is 1.8 mmol/L, 130 mg/dL is 3.4 mmol/L, and 190 mg/dL is 4.9 mmol/L.
My lab reports cholesterol in g/L. How do I convert that?
Multiply g/L by 100 to get mg/dL (1.30 g/L = 130 mg/dL), then divide by 38.67 if you need mmol/L. Some labs, for example in France, report lipids in g/L.
Track this over time in Heart Tracker
Log every lipid panel in mg/dL or mmol/L. Heart Tracker converts between them automatically, charts each number against the ranges, and lines your results up with what you were eating between tests.
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