A1C to mmol/mol Converter (IFCC) with eAG
Convert HbA1c between NGSP percent and IFCC mmol/mol with the official master equation, and see the estimated average glucose in mg/dL and mmol/L.
Last updated: October 2026
Converted HbA1c
53.01 mmol/mol
This calculator gives an estimate for general information only. It is not medical advice and does not replace a doctor, pharmacist or other qualified health professional. Always check with them before acting on the result, especially for medication doses, children, pregnancy or a medical condition, and follow the guidelines of your local health authority.
Formula below · 4 sources (niddk.nih.gov, ngsp.org, diabetes.org.uk, diabetes.org) · Updated Oct 2026
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About this calculator
HbA1c (glycated haemoglobin) is reported in two units. The NGSP (US, DCCT-aligned) scale is a percentage of total haemoglobin; the IFCC reference method reports mmol of HbA1c per mol of haemoglobin, the unit used in the UK, Australia, New Zealand and much of Europe. The two are linked by the master equation agreed by NGSP and IFCC in 2007:
IFCC (mmol/mol) = (NGSP % − 2.15) × 10.929, and NGSP % = IFCC ÷ 10.929 + 2.15.
So 6.5% is 48 mmol/mol, 7% is 53 and each 1% step is about 11 mmol/mol. The scales do not start at the same zero, which is why a simple multiplication does not work.
Estimated average glucose (eAG) is the third way to express the same number. From the ADAG study (Nathan 2008): eAG (mg/dL) = 28.7 × A1C − 46.7, and eAG (mmol/L) = 1.59 × A1C − 2.59, with A1C in NGSP percent. 7% corresponds to about 154 mg/dL (8.6 mmol/L). The tiles show the eAG in both units for whichever value you entered.
Thresholds. The ADA defines prediabetes as 5.7-6.4% (39-47 mmol/mol) and diabetes as 6.5% (48 mmol/mol) or more on two tests; the UK uses 42-47 mmol/mol (6.0-6.4%) as the at-risk range and 48 as the diagnostic cut-off. The usual treatment goal is below 7% (53 mmol/mol), individualized up to 8% (64) for older or frail adults.
As with any HbA1c, conditions that change red-cell lifespan (haemolysis, recent transfusion, iron deficiency, haemoglobin variants, pregnancy, advanced kidney disease) make the value, and so the conversion, unreliable. This converter is for information and does not replace advice from a diabetes care team.
HbA1c in NGSP percent, IFCC mmol/mol and estimated average glucose
Scroll sideways to see all columns →
| HbA1c (%) | HbA1c (mmol/mol) | eAG (mg/dL) | eAG (mmol/L) | Meaning |
|---|---|---|---|---|
| 5 | 31 | 97 | 5.4 | Normal |
| 5.7 | 39 | 117 | 6.5 | Prediabetes starts (ADA) |
| 6 | 42 | 126 | 7 | At-risk range starts (UK) |
| 6.5 | 48 | 140 | 7.8 | Diabetes diagnosed |
| 7 | 53 | 154 | 8.6 | Usual ADA goal |
| 8 | 64 | 183 | 10.1 | Above goal |
| 9 | 75 | 212 | 11.8 | Poor control |
| 10 | 86 | 240 | 13.4 | Very poor control |
How to use
Choose the direction and enter the value you have; the other box can stay blank. Example (the defaults): 7.0% → mmol/mol. (7.0 − 2.15) × 10.929 = 4.85 × 10.929 = 53.0 mmol/mol. eAG = 28.7 × 7.0 − 46.7 = 154 mg/dL, or 1.59 × 7.0 − 2.59 = 8.5 mmol/L (8.6 when calculated from the unrounded mg/dL figure). Example mmol/mol → %: a UK result of 48 mmol/mol. 48 ÷ 10.929 + 2.15 = 4.39 + 2.15 = 6.54, which rounds to 6.5%, the diagnostic threshold for diabetes on both scales.
Frequently asked questions
What is 7% HbA1c in mmol/mol?
53 mmol/mol: (7 − 2.15) × 10.929 = 53.0. Other common values: 6% is 42, 6.5% is 48, 8% is 64, 9% is 75 and 10% is 86 mmol/mol.
Why are there two units for HbA1c?
The DCCT and UKPDS trials reported HbA1c as a percentage on assays aligned by the NGSP. The IFCC later defined a reference measurement that reports the true molar ratio in mmol/mol, which is lower and starts from a different baseline. Countries that adopted IFCC reporting (the UK in 2011) use mmol/mol; the US and most trial literature still use percent, so conversion is often needed.
Is the conversion exact?
The master equation is the agreed relationship between the two reference systems and is exact for conversion purposes; laboratories report mmol/mol as a whole number and percent to one decimal, so a rounded value converts back within that rounding. The eAG, by contrast, is a population estimate with a 95% range of roughly ±15 mg/dL for an individual.
What is a normal HbA1c in mmol/mol?
Below 39 mmol/mol (5.7%) by the ADA definition of normal; the UK at-risk range starts at 42 mmol/mol (6.0%). 48 mmol/mol (6.5%) and above diagnoses diabetes on either scale.
How is eAG different from my meter or CGM average?
eAG is the average glucose predicted from HbA1c by a regression; it includes nights and times you never test. A meter average covers only the moments you test, and a CGM average over 14 days covers a shorter window. The GMI calculator does the reverse: it estimates an A1C-equivalent from a CGM mean.
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