100 mg/dL total cholesterol to mmol/L

About total cholesterol and these units

Total cholesterol is the sum of LDL, HDL, and other cholesterol-carrying lipoproteins in serum, reported on a standard lipid panel. Total cholesterol appears in mg/dL on US lab reports and in mmol/L on UK, Canadian, Australian, and most European lab reports. The factor (0.02586) is shared with LDL, HDL, and VLDL because all four reference the same cholesterol molecule.

Where the 0.02586 conversion factor comes from

mg/dL is a mass-per-volume unit. mmol/L is a moles-per-volume (molar concentration) unit. To convert between them you need the molecular weight of the substance, because that determines how many moles of it fit into a given mass.

For total cholesterol, the reference molecular weight is 386.65 g/mol (cholesterol). Working through the unit algebra:

• The factor is fixed by the molecular weight (386.65 g/mol (cholesterol)) together with the mass and volume prefixes of the two units, since a molar concentration counts molecules and a mass concentration weighs them.
• For total cholesterol this works out to 0.02586 mmol/L per mg/dL (multiply mg/dL by 0.02586 to get mmol/L).
• The inverse (mmol/L → mg/dL) is 38.67.

Step-by-step: converting 100 mg/dL of total cholesterol by hand

1. Start with the lab value: 100 mg/dL.
2. Look up the conversion factor for total cholesterol: 0.02586 mmol/L per mg/dL.
3. Multiply: 100 × 0.02586 = 2.586.
4. Attach the SI unit: 2.586 mmol/L.

Inverse check: 2.586 mmol/L ÷ 0.02586 = 100 mg/dL ✓.

Companion conversions for nearby total cholesterol values

If your lab reported a number close to but not exactly 100 mg/dL, the table below covers the surrounding range so you don't need to re-run the arithmetic.

A note on precision

Clinical chemistry assays for total cholesterol are typically precise to two or three significant figures. The exact factor 0.02586 is itself a rounded number, and the molecular weight that produces it (386.65 g/mol (cholesterol)) is conventionally rounded. So while the calculator displays 2.586 mmol/L for 100 mg/dL, reporting more decimal places than your original measurement supports is false precision.

Common questions

What is 100 mg/dL total cholesterol in mmol/L?

100 mg/dL of total cholesterol equals 2.586 mmol/L. The conversion factor for total cholesterol is 0.02586 (multiply mg/dL by 0.02586 to get mmol/L).

How do I convert mg/dL to mmol/L for total cholesterol?

total cholesterol has a conversion factor of 0.02586. Formula: 100 mg/dL × 0.02586 = 2.586 mmol/L. Inverse: 2.586 mmol/L ÷ 0.02586 = 100 mg/dL.

Why does total cholesterol have a different conversion factor than other biomarkers?

Each biomarker's mg/dL ↔ mmol/L factor is set by its molecular weight, because mmol/L is a molar concentration. For total cholesterol, the reference molecular weight is 386.65 g/mol (cholesterol), which gives a factor of 0.02586.

Where is mg/dL used and where is mmol/L used?

Total cholesterol appears in mg/dL on US lab reports and in mmol/L on UK, Canadian, Australian, and most European lab reports. The factor (0.02586) is shared with LDL, HDL, and VLDL because all four reference the same cholesterol molecule.

How precise should I report the converted value?

Lab assays for total cholesterol are typically precise to about two or three significant figures. Reporting more decimal places than your original measurement supports is false precision. For a reading of 100 mg/dL, 2.586 mmol/L is appropriate; further decimals are not.

Related conversions and reference

• Full blood test unit converter: convert any value for 50+ biomarkers in either direction.
• HbA1c ↔ average glucose converter: separate page for the HbA1c (% / mmol/mol) ↔ eAG conversion.
• Cholesterol ratio calculator: total/HDL and LDL/HDL ratios.