What is the difference between mmol/L and mg/dL?

mmol/L (millimoles per liter) measures molar concentration — the number of molecules per liter of solution. This is the SI standard used in most countries worldwide. mg/dL (milligrams per deciliter) measures mass concentration — the weight of substance per deciliter. This unit is primarily used in the United States.

Why does the conversion factor differ between substances?

The conversion factor is derived from the molecular weight of each substance. Since different molecules have different masses, converting between molar concentration (mmol/L) and mass concentration (mg/dL) requires substance-specific factors. The formula is: mg/dL = mmol/L × (molecular weight ÷ 10).

Which countries use mmol/L vs mg/dL?

mmol/L is used in most countries following the SI system, including the UK, Canada, Australia, New Zealand, and most of Europe, Asia, and Africa. mg/dL is primarily used in the United States.

How do I convert mmol/L to mg/dL manually?

Multiply the mmol/L value by the appropriate conversion factor: 18.018 for blood glucose, 38.67 for cholesterol, or 88.57 for triglycerides. Example: 5.5 mmol/L blood glucose × 18.018 = 99.1 mg/dL.

Are these conversion factors exact?

Yes, the conversion factors are based on precise molecular weights and are considered accurate for clinical purposes. The factor 18.018 for blood glucose is derived from the exact molecular weight of glucose (180.156 g/mol).

Can I use this converter for medical decisions?

This converter provides accurate unit conversions based on established molecular weights and clinical standards. However, it is intended for reference and educational purposes only. Medical decisions should always be made in consultation with qualified healthcare professionals.

Cholesterol mg/dL to mmol/L: Reverse Conversion Chart

Convert cholesterol values from mg/dL to mmol/L with quick lookup tables for total cholesterol, LDL, and HDL. Use 38.67 for cholesterol markers.

Quick Answer

For total cholesterol, LDL, HDL, and non-HDL cholesterol, convert mg/dL to mmol/L by dividing by 38.67.

mg/dL	mmol/L	Common Context
70	1.8	LDL high-risk target reference
100	2.6	LDL optimal reference
200	5.2	Total cholesterol desirable upper reference
240	6.2	Total cholesterol high reference

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200 mg/dL = 11.1 mmol/L

Total cholesterol desirable upper reference

Cholesterol Converter

Substance

Value

From: mmol/L

Result

99.1mg/dL

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This is a reverse lookup page. For the full explanation of cholesterol types, ranges, and mmol/L to mg/dL conversion, use the main Cholesterol Conversion Guide.

Formula

Direction	Formula
mg/dL to mmol/L	mg/dL ÷ 38.67
mmol/L to mg/dL	mmol/L × 38.67

This formula applies to cholesterol markers: total cholesterol, LDL cholesterol, HDL cholesterol, and non-HDL cholesterol. It does not apply to triglycerides.

Common Cholesterol mg/dL to mmol/L

Choose table format

mg/dL	mmol/L	Rounded mmol/L
70	1.81	1.8
100	2.59	2.6
130	3.36	3.4
160	4.14	4.1
190	4.91	4.9
200	5.17	5.2
220	5.69	5.7
240	6.21	6.2
260	6.72	6.7
300	7.76	7.8

Total Cholesterol Reverse Lookup

Choose table format

Total Cholesterol Category	mg/dL	mmol/L
Desirable	< 200	< 5.2
Borderline High	200-239	5.2-6.2
High	≥ 240	≥ 6.2

This table is for total cholesterol only. LDL and HDL use the same conversion factor but different interpretation ranges.

LDL and HDL Reverse Lookup

Choose table format

Marker	mg/dL Reference	mmol/L Reference	Note
LDL optimal	< 100	< 2.6	LDL is often a primary risk marker
LDL borderline high	130-159	3.4-4.1	Interpret with risk profile
LDL high	160-189	4.1-4.9	Follow-up is commonly considered
HDL low	< 40	< 1.0	Low HDL is a risk factor
HDL high	≥ 60	≥ 1.6	Often considered favorable

Use the marker name from your lab report before applying a category.

Which Formula Should You Use?

Lab Marker	Use 38.67?	Correct Formula
Total Cholesterol	Yes	mg/dL ÷ 38.67
LDL-C	Yes	mg/dL ÷ 38.67
HDL-C	Yes	mg/dL ÷ 38.67
Non-HDL-C	Yes	mg/dL ÷ 38.67
Triglycerides	No	mg/dL ÷ 88.57

The most common mistake is using the cholesterol factor for triglycerides. Use Triglycerides mg/dL to mmol/L for triglyceride values.

Same Number, Different Meaning

Value	Marker	mmol/L	Meaning Depends On
100 mg/dL	LDL	2.6	LDL target context
100 mg/dL	HDL	2.6	HDL range context
200 mg/dL	Total Cholesterol	5.2	Total cholesterol range
200 mg/dL	LDL	5.2	LDL range

The unit conversion can be identical while the interpretation changes. Do not interpret a value without confirming the marker.

FAQ

What is the cholesterol mg/dL to mmol/L formula?

Use mmol/L = mg/dL ÷ 38.67 for total cholesterol, LDL, HDL, and non-HDL cholesterol.

What is 200 mg/dL cholesterol in mmol/L?

200 mg/dL ÷ 38.67 = 5.17 mmol/L, usually rounded to 5.2 mmol/L.

What is 240 mg/dL cholesterol in mmol/L?

240 mg/dL ÷ 38.67 = 6.21 mmol/L, usually rounded to 6.2 mmol/L.

What is 100 mg/dL LDL in mmol/L?

100 mg/dL ÷ 38.67 = 2.59 mmol/L, usually rounded to 2.6 mmol/L.

Does HDL use the same conversion factor as LDL?

Yes. HDL and LDL both use 38.67, but their ranges are interpreted differently.

Does this formula work for triglycerides?

No. Triglycerides use 88.57. Use the triglycerides-specific converter for triglyceride values.

Related Resources

Cholesterol mmol/L to mg/dL - Main cholesterol conversion guide
LDL Cholesterol mmol/L to mg/dL - LDL-specific conversion and targets
HDL Cholesterol mmol/L to mg/dL - HDL-specific conversion and ranges
Triglycerides mg/dL to mmol/L - Triglycerides reverse conversion

References

Mayo Clinic. Cholesterol test
American Heart Association. What Your Cholesterol Levels Mean
Centers for Disease Control and Prevention. About Cholesterol
National Heart, Lung, and Blood Institute. Blood Cholesterol

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Medical Disclaimer: This page is for unit conversion and general education only. Cholesterol results should be interpreted by a healthcare professional in the context of your full lipid panel and cardiovascular risk profile.