mmol/L to mg/dL Calculator

The process is simple once you know what you're working with. The two units measure the same thing (concentration of a substance in blood) but on different scales. The United States uses mg/dL almost exclusively, while most other countries report in mmol/L. So if you get lab results from abroad, or you're using a glucose meter bought overseas, you'll need to convert.

To go from mmol/L to mg/dL, you multiply by a conversion factor. That factor depends on the substance being measured. For blood glucose, the factor is 18.0182. For cholesterol and triglycerides, it's 38.67 and 88.57, respectively. Each substance has a different molecular weight, which is why the multiplier changes.

There's no complicated setup here. Identify what you're measuring, grab the right factor, and multiply. That's it.

The general formula looks like this:

mg/dL = mmol/L × conversion factor

For blood glucose specifically:

mg/dL = mmol/L × 18.0182

So if your glucose reading is 5.5 mmol/L, the calculation is: 5.5 × 18.0182 = 99.1 mg/dL.

For total cholesterol or LDL/HDL:

mg/dL = mmol/L × 38.67

For triglycerides:

mg/dL = mmol/L × 88.57

Going the other direction (mg/dL back to mmol/L) is just as easy. Divide by the same factor instead of multiplying. If your glucose is 126 mg/dL, divide by 18.0182 and you get roughly 7.0 mmol/L.

If you'd rather skip the math and just look up your number, this chart covers the most common blood glucose values in both units.

Values are rounded to the nearest whole number. Use these as quick reference points, but run the full formula when precision matters.

Blood glucose is probably the most common reason people need this conversion. Diabetes management tools, continuous glucose monitors, and lab reports don't all agree on units, especially when you're crossing borders or sourcing devices internationally.

The standard conversion factor for glucose is 18.0182, which comes from glucose's molecular weight of 180.182 g/mol. In practice, most sources round this to 18 for quick mental math, and the difference is negligible for clinical purposes.

Here's a quick look at key glucose thresholds in both units:

• Normal fasting glucose: 3.9–5.5 mmol/L (70–99 mg/dL)
• Prediabetes range: 5.6–6.9 mmol/L (100–125 mg/dL)
• Diabetes diagnosis threshold: 7.0 mmol/L or higher (126 mg/dL or higher)
• Hypoglycemia warning: Below 3.9 mmol/L (below 70 mg/dL)
• Hyperglycemia concern: Above 10.0 mmol/L (above 180 mg/dL)

Knowing these benchmarks in both units helps you interpret readings no matter what format they come in.

Cholesterol and triglyceride levels also get reported in mmol/L outside the U.S., so this comes up regularly for anyone tracking cardiovascular health with international labs or guidelines.

The conversion factors differ from glucose because these molecules have different molecular weights:

For reference, desirable total cholesterol in the U.S. is under 200 mg/dL (about 5.17 mmol/L). An HDL above 60 mg/dL (1.55 mmol/L) is considered protective. Triglycerides below 150 mg/dL (1.69 mmol/L) fall in the normal range.

When you're comparing results from different countries or different lab systems, always double-check which unit the report is using before drawing any conclusions about your numbers.

Seeing the math worked out a few different ways makes it stick. Here are some practical examples across substances:

• Blood glucose of 6.1 mmol/L: 6.1 × 18.0182 = 109.9 mg/dL (approximately 110 mg/dL)
• Blood glucose of 9.0 mmol/L: 9.0 × 18.0182 = 162.2 mg/dL
• Total cholesterol of 4.5 mmol/L: 4.5 × 38.67 = 174.0 mg/dL
• LDL cholesterol of 3.0 mmol/L: 3.0 × 38.67 = 116.0 mg/dL
• HDL cholesterol of 1.2 mmol/L: 1.2 × 38.67 = 46.4 mg/dL
• Triglycerides of 2.0 mmol/L: 2.0 × 88.57 = 177.1 mg/dL

Notice that the cholesterol and triglyceride factors produce much larger mg/dL values relative to mmol/L. That's purely a reflection of their molecular weights, not an indication that the levels themselves are dramatically different.

Both units measure concentration, just in different ways. mmol/L stands for millimoles per liter. A mole is a standardized count of molecules (based on Avogadro's number), so mmol/L tells you how many molecules of a substance are present in a given volume of blood. It's the unit preferred in most of the world and recommended by the International System of Units (SI).

mg/dL stands for milligrams per deciliter. It measures the mass of the substance rather than the number of molecules. The U.S. stuck with this system historically, and it's still the standard in American clinical practice.

Neither unit is more accurate than the other. They're just two ways of describing the same measurement. The conversion factor bridges the two by accounting for the molecular weight of the substance in question. Heavier molecules have a larger factor, lighter ones have a smaller one.

For patients managing chronic conditions, understanding both units means you can read results from any lab, use devices purchased anywhere, and follow guidelines from international health organizations without getting confused.

This conversion comes up more often than most people expect. A few scenarios where you'll genuinely need it:

• Traveling internationally: Blood glucose meters sold in Canada, the UK, Australia, and most of Europe display mmol/L by default. If you usually track in mg/dL, you'll need to convert or switch the device settings.
• Reading foreign lab reports: If you've had bloodwork done abroad or your doctor references international studies, results may be in mmol/L.
• Following global health guidelines: The World Health Organization and many international diabetes organizations publish thresholds in mmol/L. Converting lets you apply those guidelines to your own U.S.-format results.
• Comparing research: Medical journals from outside the U.S. often use mmol/L. If you're reading studies on cholesterol, blood sugar, or other metabolic markers, conversion helps you put numbers in context.
• Managing diabetes abroad: Travelers with diabetes frequently run into unit mismatches when buying supplies or consulting local healthcare providers.

Having a reliable conversion method, whether it's a calculator, a chart, or just memorizing the factor of 18 for glucose, takes a small but real source of confusion off the table.