Medical Unit Converter

Lab results travel badly. A glucose of 6.2 on a British report and 112 on an American one are the same blood.
The US reports most blood chemistry in milligrams per decilitre (mg/dL). The UK, Europe, Canada and Australia use SI units: millimoles per litre (mmol/L), or micromoles per litre (µmol/L) for creatinine and uric acid.

The formula

mmol/L = mg/dL ÷ factor, and for the two µmol/L tests, µmol/L = mg/dL × factor

The factor comes from the molecule’s molar mass. A millimole of glucose weighs 180.16 mg, so 1 mmol/L of glucose is about 18 mg/dL. Every analyte weighs something different, which is why each one has its own number:

Using glucose’s 18 on a cholesterol result is the classic mistake. It gives a figure barely half what it should be.

Worked example: a UK report reads glucose 6.2 mmol/L, total cholesterol 5.8 mmol/L and creatinine 88 µmol/L.

• Glucose: 6.2 × 18.0156 = 111.7 mg/dL, in the prediabetes band if it was a fasting sample
• Cholesterol: 5.8 × 38.67 = 224.3 mg/dL, borderline high
• Creatinine: 88 ÷ 88.42 = 1.00 mg/dL, inside the usual adult range

The bands this page shows, in mg/dL

• Fasting glucose, from the American Diabetes Association: under 70 is low, 70 to 99 normal, 100 to 125 prediabetes, 126 or more diabetes
• Total cholesterol: under 200 desirable, 200 to 239 borderline high, 240 or more high
• LDL: under 100 optimal, 100 to 129 near optimal, 130 to 159 borderline high, 160 to 189 high, 190 or more very high
• HDL: under 40 is low for men and under 50 for women, and 60 or more is protective
• Triglycerides: under 150 normal, 150 to 199 borderline high, 200 to 499 high, 500 or more very high

The cholesterol and triglyceride bands are the US National Cholesterol Education Program’s (ATP III). Treatment targets now depend on your overall heart risk rather than on one number, so treat these as a way to read a report, not a goal.

Labs also set their own reference intervals, and the one printed on your report beats any generic table, this one included. Creatinine in particular moves with muscle mass, so a range is all a converter can honestly offer.

The thousandfold trap. Creatinine and uric acid come in micromoles, not millimoles. A creatinine of 0.088 mmol/L is the same thing as 88 µmol/L, and forums mix the two up all the time. If a converted number looks a thousand times too small or too large, that is almost always what happened.