Unit Conversion

Blood Sugar Converter

Enter a blood glucose reading to convert instantly between mg/dL (used in the US and a few other countries) and mmol/L (used in most of the rest of the world) — helpful when comparing a meter reading against a chart or reference that uses the other unit.

Convert reading

Converted value

How the Blood Sugar Converter formula works

The conversion factor between the two units:

mmol/L = mg/dL / 18.0182
mg/dL = mmol/L × 18.0182

Step-by-step calculation

  1. To convert mg/dL to mmol/L, divide by 18.0182.
  2. To convert mmol/L to mg/dL, multiply by 18.0182.

Worked example

A reading of 126 mg/dL: 126 / 18.0182 ≈ 7.0 mmol/L. A reading of 5.5 mmol/L: 5.5 × 18.0182 ≈ 99 mg/dL.

Frequently asked questions

Why do different countries use different blood sugar units?

It's a historical difference in measurement convention — mg/dL measures mass concentration, while mmol/L measures molar concentration. The US and a small number of other countries use mg/dL, while most of the world, including the UK, Canada, and Australia, uses mmol/L.

Is this conversion exact?

Yes — 18.0182 is the precise conversion factor based on glucose's molar mass, so this conversion is mathematically exact, not an approximation.