HbA1c (glycated hemoglobin)
HbA1c, glycated hemoglobin, reflects the average blood sugar over the last 2–3 months. It does not depend on breakfast.
At a glance
- Sample
- Blood
- Units
- % (US), mmol/mol (Europe)
- Often looked at with
- Glucose, Insulin
- Preparation
- You do not need to fast: the result does not depend on your last meal.
Units: % and mmol/mol
US labs print HbA1c as a percentage (NGSP); many European labs print it in mmol/mol (IFCC). The two are linked by the IFCC–NGSP master equation.
mmol/mol = (% − 2.15) × 10.929 · the IFCC–NGSP master equation
This converter changes units only. It doesn’t tell you whether a number is in or out of any range: that depends on the range printed by your own lab, and on your doctor. Soma does not diagnose and is not medical advice.
HbA1c % to mmol/mol: converter and every value · Estimated average glucose from HbA1c
Why lab ranges differ
Each lab sets its reference range for its own method and analyser, and many ranges differ by age and sex. Two labs can print different ranges for the same blood, so a result is read against the range on its own report, not against a number from another lab or a website.
Soma charts every HbA1c result against the range printed by the lab that measured it.
What can affect the result
- Anemia of any type.
- Some inherited variants of hemoglobin.
- It shows the average over 2–3 months, so it does not react to a single day.
If something like this applies, mention it to the doctor who reads your results.
Questions
How do I convert HbA1c from % to mmol/mol?
Subtract 2.15 and multiply by 10.929. For example, 6.5% is 47.5 mmol/mol.
Why does my lab’s HbA1c range differ from another lab’s?
Each lab sets its range for its own method and equipment, and many ranges differ by age and sex. That’s why a result is best read against the range printed on the same report.
How do I prepare for a HbA1c test?
You do not need to fast: the result does not depend on your last meal. Follow your lab’s instructions.
Related tests
Got a lab report with HbA1c?
Share it to Soma: it reads every row on your phone, with no account and no upload, and puts your HbA1c on one chart with your earlier results, each against the range your lab printed.
Sources
- Hemoglobin A1C (HbA1c) Test — MedlinePlus, U.S. National Library of Medicine.
- Units: the IFCC–NGSP master equation, as the Soma app converts.
Mention of a source doesn’t mean it endorses Soma. This page explains the test; it doesn’t diagnose and is not medical advice. Talk to your doctor about what your results mean.