100 mg/dL LDL cholesterol to mmol/L

The answer, the conversion factor and where it comes from, a step-by-step manual calculation, and a companion table of nearby LDL cholesterol values in both units. Mechanical unit conversion only. This page does not interpret the value clinically.

Answer
100 mg/dL = 2.586 mmol/L
100 mg/dL × 0.02586 = 2.586 mmol/L
For interpretation of what this LDL cholesterol value means for you, refer to your lab's reference range and your healthcare provider. This page is unit conversion only.

About LDL cholesterol and these units

LDL ("low-density lipoprotein") cholesterol is one of the lipid fractions reported on a standard lipid panel. LDL 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 HDL, VLDL, and total cholesterol because all three 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 LDL 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 LDL 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 LDL cholesterol by hand

  1. Start with the lab value: 100 mg/dL.
  2. Look up the conversion factor for LDL 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 LDL 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.

mg/dLmmol/L
250.6465
501.293
751.94
902.327
1002.586
1102.845
1253.232
1503.879
1754.526
2005.172
2506.465
3007.758

A note on precision

Clinical chemistry assays for LDL 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 LDL cholesterol in mmol/L?

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

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

LDL 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 LDL 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 LDL 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?

LDL 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 HDL, VLDL, and total cholesterol because all three reference the same cholesterol molecule.

How precise should I report the converted value?

Lab assays for LDL 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

Medical Disclaimer: This page performs a mechanical unit conversion and provides background on the units themselves. It is not a clinical interpretation. Whether any specific LDL cholesterol value is within range for you depends on your lab's reference range, your individual baseline, and clinical context. Discuss specific results with your healthcare provider.

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