Two numbering systems for HbA1c coexist worldwide, the familiar percentage and the IFCC millimoles per mole used in the UK and much of Europe. This converter flips percentage into mmol/mol instantly.
Your visual report appears here
Fill in the form and press Calculate. You will get your number, an interpretation chip, and a personalized chart pack drawn instantly in your browser.
- Risk spectrum with your position marked
- Reference ranges from the original publication
- Shareable link, nothing stored
Scientific references
One test, two dialects
HbA1c results arrived in the United States as a percentage of hemoglobin carrying sugar, and that convention spread through the DCCT trial into guidelines everywhere. In 2007 the International Federation of Clinical Chemistry pushed a purer unit, millimoles of glycated hemoglobin per mole of total hemoglobin, arguing it reflected the actual chemistry. Britain, most of Europe, and many other regions adopted the new numbers, while the United States and Japan stayed with percentages. Travelers, expats, and anyone reading international research now bump into both dialects constantly.
The conversion line
The relationship is a straight line. Multiply the percentage by 10.93 and subtract 23.5 to get mmol/mol. The diagnostic threshold of 6.5 percent becomes 48 mmol/mol, and the common treatment target of 7 percent becomes 53. The reverse trip divides the IFCC value by 10.93 after adding 23.5, handy when a British report lands in an American chart.
Why the numbers look so different
The IFCC scale deliberately abandoned percentages to prevent confusion with other glycation measures, which is why the values run much larger than their percent twins for the same patient. A person at 8 percent reads 64 mmol/mol. Neither number is more accurate, they simply answer with different rulers, and every lab knows its local dialect.
Reading foreign guidelines safely
European diabetes guidelines quote targets in mmol/mol, American ones in percent. Before applying any published target to your own result, confirm which unit your lab reported. Most lab slips now print both numbers side by side, and this converter covers the gap when they do not.