Cholesterol Units Converter

Why cholesterol units differ worldwide

Clinical laboratories report cholesterol concentration in either milligrams per deciliter, written mg/dL, or millimoles per liter, written mmol/L.

The first is a mass concentration and the second is an amount-of-substance concentration. US reports commonly use mg/dL, while many other countries use mmol/L. Total cholesterol, LDL cholesterol, HDL cholesterol, non-HDL cholesterol, and VLDL cholesterol all refer to the mass of cholesterol within different lipoprotein fractions. They use the same cholesterol conversion factor. Triglycerides are different molecules with a different molecular mass, so they require a different factor.

Conversion changes the number and unit, not the blood sample or underlying concentration. An LDL-C result of 116 mg/dL and 3.00 mmol/L describe the same concentration after rounding. Keep the original report because reference intervals, flags, and calculation methods belong to the laboratory that produced it.

[1][2][3]

Cholesterol conversion formula

To convert cholesterol from mg/dL to mmol/L, multiply by 0.02586. This is equivalent to dividing by 38.67. To convert cholesterol from mmol/L to mg/dL, multiply by 38.67.

The factor reflects cholesterol’s molecular mass and the volume conversion between deciliters and liters. Use the cholesterol factor only for total cholesterol, LDL-C, HDL-C, non-HDL-C, and VLDL-C. Apolipoprotein B is a protein concentration. Lipoprotein(a) mass cannot be reliably converted to particle concentration with one fixed factor because apo(a) isoform size varies.

For triglycerides, mg/dL to mmol/L uses 0.01129, equivalent to division by 88.57. Triglycerides in mmol/L convert to mg/dL by multiplication by 88.57. Applying 38.67 to triglycerides creates an incorrect result.

[1][2][4]

Worked conversion examples

Example 1 converts LDL-C of 130 mg/dL: 130 × 0.02586 = 3.3618 mmol/L. Rounded to two decimal places, the result is 3.36 mmol/L.

A clinical report may round to 3.4 mmol/L, which does not represent a meaningful disagreement. Example 2 converts HDL-C of 1.40 mmol/L: 1.40 × 38.67 = 54.138 mg/dL. Rounded to a whole number, the result is 54 mg/dL. Preserve more digits during calculation and round only the final result.

Example 3 converts triglycerides of 2.00 mmol/L: 2.00 × 88.57 = 177.14 mg/dL, usually reported as 177 mg/dL. Using the cholesterol factor would produce 77 mg/dL, a large error that could change interpretation.

[1][2][4]

How to use this cholesterol units converter

Choose the analyte first. Select cholesterol for total cholesterol, LDL-C, HDL-C, non-HDL-C, or VLDL-C. Select triglycerides only for a triglyceride result.

Copy the numerical value and source unit exactly from the laboratory report before calculating. Check whether the source uses mg/dL or mmol/L, then choose the desired output unit. Convert once, round at the end, and label the result. A bare number such as 4.2 has no safe clinical meaning without its analyte and unit.

Compare the converted result only with a threshold for the same analyte. LDL-C should not be compared with total cholesterol, and non-HDL-C should not be compared with an LDL-C goal. Keep fasting status, collection date, and laboratory method attached to the result.

Use the conversion to read guidelines, research, or records from another country. Do not use it to select treatment. A clinician interprets the value with cardiovascular history, diabetes, blood pressure, smoking, kidney function, family history, age, pregnancy, and current medicine.

[1][3][5]

Common values shown in both units

Traditional adult reporting values include total cholesterol below 200 mg/dL, about 5.17 mmol/L, and LDL-C below 100 mg/dL, about 2.59 mmol/L. These are common descriptive values, not universal treatment goals.

Current lipid treatment uses risk-specific thresholds and percentage reduction. Triglycerides of 150 mg/dL convert to 1.69 mmol/L. A severe level of 500 mg/dL converts to 5.64 mmol/L. LDL-C of 190 mg/dL converts to 4.91 mmol/L and prompts evaluation for severe hypercholesterolemia in US guidance.

Guidelines often round converted thresholds for readability. A source may pair 190 mg/dL with 4.9 mmol/L and another with 5.0 mmol/L. Use the threshold in the guideline’s native unit when a treatment decision sits near a boundary, and ask the clinician how rounding is handled.

[1][2][5]

Rounding and apparent discrepancies

Most US lipid reports use whole mg/dL values. Reports in mmol/L often use one or two decimal places.

Conversion can therefore produce more digits than the original measurement supports. Reporting 3.3618 mmol/L from an LDL-C recorded as 130 mg/dL implies precision that the source does not provide. For personal records, two decimal places in mmol/L and a whole number in mg/dL are usually adequate. Keep unrounded values during multi-step calculations. If converting a treatment threshold, retain enough precision to reproduce the source and show the rounded clinical value separately.

Reverse conversion may not return the original whole number after rounding. For example, 130 mg/dL becomes 3.36 mmol/L, and 3.36 × 38.67 becomes 129.93 mg/dL. This is the expected effect of rounding, not a change in cholesterol.

[1][2][4]

Laboratory and test context still applies

Unit conversion does not correct preanalytic or analytic problems.

Recent food intake mainly affects triglycerides, while acute illness, pregnancy, major weight change, thyroid disease, diabetes control, kidney or liver disease, alcohol, and medicines can change a lipid profile. Interpret the converted value under the same conditions as the original. Nonfasting lipid panels are acceptable for initial assessment in many adults. A fasting repeat can be useful with high triglycerides, suspected inherited dyslipidemia, or an unexpected result. The need for fasting comes from the clinical question, not from the unit system.

Calculated LDL-C depends on the equation used. Converting a Friedewald LDL result into mmol/L does not improve its accuracy at high triglycerides or low LDL-C. Laboratory reports should state whether LDL-C was calculated or measured and identify the calculation method when possible.

[1][2][6]

Do not reuse the factor for other tests

Glucose, creatinine, uric acid, bilirubin, calcium, and other laboratory analytes each require a molecular or equivalent-specific factor. A cholesterol conversion tool should not be used for them.

The same written units do not imply the same conversion factor. Apolipoprotein B and apolipoprotein A-I are commonly reported in mg/dL or g/L, which is a metric volume conversion rather than a cholesterol molar conversion. Converting mg/dL to g/L multiplies by 0.01. Do not label that result mmol/L.

Lipoprotein(a) may be reported as mg/dL or nmol/L, but no fixed conversion accurately links mass and molar units for all people because apo(a) isoform size varies. Laboratory guidance recommends reporting the assay’s native unit rather than applying a universal factor.

[2][7][8]

Population and guideline caveats

The arithmetic factor is the same across age, sex, pregnancy, and ancestry because it describes cholesterol’s molecular mass. Interpretation is not the same.

Children use pediatric reference values, pregnancy changes expected lipid concentrations, and treatment goals differ with cardiovascular risk and medical history. Regional guidelines may use different risk equations, treatment thresholds, and target strategies even after the units match. A converted number should be read within the source guideline’s population, date, and clinical scope. Unit agreement does not make two guidelines equivalent.

Risk categories also depend on whether a value is measured or calculated and on the sample context. When transferring care between countries, provide the full original report, medication list, collection date, fasting status, and clinical history rather than a converted number alone.

[1][3][5][9]

Limitations and when confirmation is required

This converter performs dimensional arithmetic only.

It does not validate the source result, identify the analyte, assess laboratory quality, calculate cardiovascular risk, or diagnose a lipid disorder. A plausible converted number can still come from the wrong input or wrong conversion category. Check the original report or contact the laboratory when the unit is missing, the analyte name is ambiguous, a converted result conflicts with the report, or LDL methodology is unclear. Clinical confirmation is required before changing medicine and for LDL-C at or above 190 mg/dL, triglycerides at or above 500 mg/dL, or suspected inherited dyslipidemia.

Seek urgent medical care for chest pressure, sudden weakness or speech difficulty, or severe abdominal pain with very high triglycerides. Unit conversion does not assess symptoms. For routine results, a clinician can place the number in a risk-based prevention plan and decide whether repeat testing is needed.

[2][3][5][6]

How it works

mg/dL = mmol/L × 38.67 for total cholesterol, LDL, and HDL.

Frequently asked questions

• How to convert LDL mmol/L to mg/dL?Multiply mmol/L by 38.67 to get mg/dL.

Related calculators

References

1. Grundy et al.. 2018 Guideline on the Management of Blood Cholesterol
2. Association for Diagnostics and Laboratory Medicine. Guidance on the Measurement and Reporting of Lipids and Lipoproteins
3. CDC. About Cholesterol
4. National Institute of Standards and Technology. SI Unit Conversion Guide
5. ACC and AHA Joint Committee on Clinical Practice Guidelines. 2026 Guideline on the Management of Dyslipidemia
6. National Heart, Lung, and Blood Institute. Blood Cholesterol
7. Langlois et al.. Standardization of Apolipoprotein B, LDL-C, and Non-HDL-C
8. Kronenberg et al.. Lipoprotein(a) Measurement and Clinical Management
9. American Diabetes Association. Cardiovascular Risk Reduction in Diabetes: Standards of Care