Cholesterol Units Converter: mg/dL to mmol/L
Enter any cholesterol or triglyceride reading and choose your starting unit. The converter instantly produces the value in the opposite unit for all four main lipid types: total cholesterol, LDL, HDL, and triglycerides. Reference ranges and a risk category are shown alongside each result so you can put the number in context.
Why two units exist for cholesterol
Most English-speaking countries historically reported cholesterol in milligrams per decilitre (mg/dL), a convention inherited from early American clinical labs. Most of the rest of the world adopted the International System of Units (SI), which expresses cholesterol concentration in millimoles per litre (mmol/L). The same underlying measurement, simply presented at a different numerical scale. Because clinical guidelines, research papers, and lab reports can be written in either system, healthcare professionals and patients frequently need to convert between them. The conversion factor for cholesterol (total, LDL, HDL) is 0.02586 (mg/dL to mmol/L) or 38.67 (mmol/L to mg/dL). Triglycerides use a different factor (0.01129 or 88.57) because their molecular weight is much higher.
The four lipids and what they mean
A standard lipid panel measures four values. Total cholesterol is the overall amount of cholesterol in your blood; desirable is below 200 mg/dL (5.17 mmol/L). LDL (low-density lipoprotein) is often called "bad" cholesterol because elevated levels drive plaque build-up in arteries; optimal is below 100 mg/dL (2.59 mmol/L) for most adults, or below 70 mg/dL (1.81 mmol/L) for those at very high cardiovascular risk. HDL (high-density lipoprotein) is the "good" cholesterol that ferries cholesterol away from arteries; levels of 60 mg/dL (1.55 mmol/L) or above are protective, while levels below 40 mg/dL (1.03 mmol/L) are a major independent risk factor. Triglycerides are fats in the blood derived from calories the body does not immediately use; normal is below 150 mg/dL (1.69 mmol/L) on a fasting sample.
How to use the converter
Select "mg/dL to mmol/L" or "mmol/L to mg/dL" from the first dropdown, then choose the lipid type from the second dropdown. Enter the value from your lab report. The converter shows the result in the opposite unit, the conversion factor used, and your risk category based on standard clinical thresholds. If you have a full lipid panel, run each value separately by switching the lipid type dropdown. The reference table below the converter shows the complete set of thresholds in both units so you can read your entire panel at a glance.
Limitations and when to see a clinician
This tool performs a unit conversion only. The reference ranges shown follow the American Heart Association and NCEP ATP III guidelines for adults and apply to fasting samples for triglycerides. They are not adjusted for age, sex, ethnicity, diabetes, kidney disease, or existing cardiovascular disease, all of which can change the treatment target. A single out-of-range value does not automatically mean you need medication; clinicians consider the full lipid panel, non-HDL cholesterol, the total-cholesterol-to-HDL ratio, and your overall 10-year cardiovascular risk. If any value is outside the normal range, schedule a review with your doctor or a pharmacist rather than adjusting medications independently.
Lipid reference ranges (adults)
| Lipid | mg/dL | mmol/L | Category |
|---|---|---|---|
| Total cholesterol | < 200 | < 5.17 | Desirable |
| Total cholesterol | 200-239 | 5.17-6.18 | Borderline high |
| Total cholesterol | >= 240 | >= 6.21 | High |
| LDL cholesterol | < 100 | < 2.59 | Optimal |
| LDL cholesterol | 100-129 | 2.59-3.34 | Near optimal |
| LDL cholesterol | 130-159 | 3.36-4.11 | Borderline high |
| LDL cholesterol | 160-189 | 4.14-4.89 | High |
| LDL cholesterol | >= 190 | >= 4.91 | Very high |
| HDL cholesterol | < 40 | < 1.03 | Low (major risk factor) |
| HDL cholesterol | 40-59 | 1.03-1.53 | Acceptable |
| HDL cholesterol | >= 60 | >= 1.55 | High (protective) |
| Triglycerides | < 150 | < 1.69 | Normal |
| Triglycerides | 150-199 | 1.69-2.25 | Borderline high |
| Triglycerides | 200-499 | 2.26-5.64 | High |
| Triglycerides | >= 500 | >= 5.65 | Very high |
American Heart Association and NCEP ATP III adult reference ranges. Triglyceride thresholds apply to fasting samples.
Frequently asked questions
What is the formula to convert mg/dL to mmol/L for cholesterol?
Multiply the mg/dL value by 0.02586. For example, 200 mg/dL x 0.02586 = 5.17 mmol/L. This factor applies to total cholesterol, LDL, and HDL. For triglycerides, use 0.01129 instead, because triglycerides have a higher molecular weight (roughly 885 g/mol versus 387 g/mol for cholesterol).
What is the formula to convert mmol/L to mg/dL for cholesterol?
Multiply the mmol/L value by 38.67. For example, 5.17 mmol/L x 38.67 = 199.9 mg/dL. For triglycerides in mmol/L, multiply by 88.57 instead.
Why do triglycerides use a different conversion factor than cholesterol?
Because the two substances have different molecular weights. Cholesterol (C27H46O) has a molecular weight of approximately 386.65 g/mol, giving the factor 10 / 386.65 = 0.02586. A typical triglyceride molecule weighs roughly 885 g/mol, giving the factor 10 / 885 = 0.01129. Since mmol/L means millimoles - a count of molecules - per litre, heavier molecules produce a smaller mmol/L number for the same mass concentration.
Is 5.2 mmol/L total cholesterol normal?
5.2 mmol/L equals about 201 mg/dL, which falls in the "borderline high" range (200-239 mg/dL / 5.17-6.18 mmol/L). It is just above the desirable threshold of 5.17 mmol/L (200 mg/dL). A single borderline reading does not necessarily require treatment; your doctor will consider the full panel and your overall risk profile.
What is a healthy LDL cholesterol level in mmol/L?
The general optimal LDL target for most healthy adults is below 2.59 mmol/L (100 mg/dL). For people with existing heart disease, diabetes, or multiple risk factors, the target is often below 1.81 mmol/L (70 mg/dL). Very high-risk patients may have targets below 1.40 mmol/L (55 mg/dL) under European guidelines. Your clinician sets the target based on your individual risk.
Does this converter work for non-HDL cholesterol or VLDL?
Non-HDL cholesterol and VLDL cholesterol are derived from the lipid panel values rather than measured directly, but both are still types of cholesterol, so the same conversion factor applies: multiply mg/dL by 0.02586 or mmol/L by 38.67. Select "Total cholesterol" as the lipid type in this converter for non-HDL or VLDL readings.