mmol/L to mg/dL Converter
Convert lab values between mmol/L and mg/dL. Choose the analyte — glucose, total/HDL/LDL cholesterol, or triglycerides — because each uses its own molar-mass factor, then enter a value in either direction.
Example: with Value 5.5 · Analyte Glucose · Direction mmol/L → mg/dL → Result: 99.09 mg/dL.
- In words5.5 mmol/L Glucose (fasting) = 99.09 mg/dL
- Typical referenceNormal 70-99 mg/dL (3.9-5.5 mmol/L)
- Factor usedGlucose (fasting): mg/dL = mmol/L × 18.016
Computed by the calculator below using its default values. Change any input to see your own numbers.
mg/dL = mmol/L × (molar mass ÷ 10). Glucose uses 18.016, cholesterol 38.67, triglycerides 88.57 — the factors differ because the molecules differ.
Why each analyte has its own factor
Most of the world reports blood results in mmol/L (millimoles per liter, a count of molecules), while the US uses mg/dL (a mass per volume). Converting between them means multiplying by the molecule's molar mass and dividing by 10. Glucose weighs 180.16 g/mol, so the factor is 18.016; cholesterol is 386.7 g/mol (factor 38.67); triglycerides average about 885.7 g/mol (factor 88.57). HDL and LDL are cholesterol, so they share the 38.67 factor.
That is why you cannot use one number for everything: a glucose of 5.5 mmol/L is 99 mg/dL, but a cholesterol of 5.5 mmol/L is 213 mg/dL. Pick the analyte and the direction, and the matching factor is applied.
How it’s calculated
mg/dL = mmol/L × (molar mass g/mol ÷ 10). Factors: glucose 18.016 (MW 180.16), cholesterol including HDL/LDL 38.67 (MW 386.7), triglycerides 88.57 (assumed mean MW ~885.7). Reverse divides. Reference ranges: ADA (glucose), NCEP ATP III / AHA (lipids).
Triglyceride conversion uses an assumed average molecular weight, so labs may round slightly differently; ranges are general adult guides, not personal targets. Not medical advice.
Conversion factors and typical ranges
| Analyte | mmol/L × factor | Typical reference |
|---|---|---|
| Glucose (fasting) | × 18.016 | 70-99 mg/dL / 3.9-5.5 mmol/L |
| Total cholesterol | × 38.67 | < 200 mg/dL / < 5.17 mmol/L |
| HDL cholesterol | × 38.67 | ≥ 40-60 mg/dL |
| LDL cholesterol | × 38.67 | < 100 mg/dL / < 2.59 mmol/L |
| Triglycerides | × 88.57 | < 150 mg/dL / < 1.7 mmol/L |
Molar-mass factors; ranges from ADA and NCEP ATP III / AHA guidelines.
Common mistakes
- Using the glucose factor (18) for cholesterol or triglycerides — each has a different molar mass.
- Mixing up direction: multiply going mmol/L to mg/dL, divide going the other way.
- Comparing a lipid panel in mg/dL to a range quoted in mmol/L without converting first.
- Reading a converted number as a diagnosis rather than a value to discuss with a clinician.
Frequently asked questions
How do I convert glucose from mmol/L to mg/dL?
Multiply by 18.016. A fasting glucose of 5.5 mmol/L is about 99 mg/dL. To go the other way, divide mg/dL by 18.016.
Why is the cholesterol factor different from glucose?
The factor is the molecule's molar mass divided by 10. Cholesterol is heavier than glucose, so its factor is 38.67 versus 18.016.
Do HDL and LDL use the same factor as total cholesterol?
Yes. HDL and LDL are forms of cholesterol, so all three convert with 38.67. Only triglycerides and glucose use different numbers.
What do these numbers mean for my health?
Reference ranges are general guides; your targets depend on age, history, and risk factors. Interpret any lab value with the clinician who ordered it.