HbA1c and blood sugar converter

HbA1c in % is mmol/mol ÷ 10.929 + 2.15. 48 mmol/mol is 6.5 %, the limit for diabetes. Blood sugar in mg/dL is mmol/L × 18.

HbA1c conversion table

HbA1c %	mmol/mol	Average blood sugar
5.0 %	31	5.4 mmol/L · 97 mg/dL
5.5 %	37	6.2 mmol/L · 111 mg/dL
5.7 %	39	6.5 mmol/L · 117 mg/dL
6.0 %	42	7.0 mmol/L · 125 mg/dL
6.5 %	48	7.8 mmol/L · 140 mg/dL
7.0 %	53	8.6 mmol/L · 154 mg/dL
7.5 %	58	9.4 mmol/L · 169 mg/dL
8.0 %	64	10.2 mmol/L · 183 mg/dL
8.5 %	69	10.9 mmol/L · 197 mg/dL
9.0 %	75	11.7 mmol/L · 212 mg/dL
9.5 %	80	12.5 mmol/L · 226 mg/dL
10.0 %	86	13.3 mmol/L · 240 mg/dL
11.0 %	97	14.9 mmol/L · 269 mg/dL
12.0 %	108	16.5 mmol/L · 298 mg/dL

Blood sugar conversion table

mmol/L	mg/dL
3.0	54
4.0	72
5.0	90
5.6	101
6.1	110
7.0	126
7.8	141
8.0	144
9.0	162
10.0	180
11.1	200
12.0	216
15.0	270
20.0	360

Questions

How do I convert HbA1c from % to mmol/mol?

Subtract 2.15 and multiply by 10.929: 6.5 % is (6.5 − 2.15) × 10.929 = 48 mmol/mol. The other way, divide by 10.929 and add 2.15. This is the IFCC–NGSP master equation, and the Kairi app uses the same one.

What is a normal HbA1c?

Under 42 mmol/mol (6.0 %) is the typical range. 42–47 mmol/mol (6.0–6.4 %) means a raised risk of type 2 diabetes in the Danish guidelines, and is often called prediabetes. 48 mmol/mol (6.5 %) or more is the limit for diabetes, confirmed by a second test on another day. In the US the prediabetes range starts lower, at 5.7 % (39 mmol/mol).

How do I convert blood sugar from mmol/L to mg/dL?

Multiply by 18 (18.016 exactly): 7.0 mmol/L is 126 mg/dL. From mg/dL to mmol/L, divide by 18.

What is estimated average glucose (eAG)?

The average blood sugar that goes with an HbA1c, from the ADAG study (Nathan et al., 2008): 28.7 × HbA1c % − 46.7 mg/dL. It is an average across many people, and an individual’s real average can sit some way either side.

Why are there two units for HbA1c?

The US reports HbA1c in %. Denmark, the UK and many other countries report it in mmol/mol, the international IFCC unit. Both describe the same blood test.

Sources

Dansk Endokrinologisk Selskab: Type 2-diabetes, nationale behandlingsvejledninger. endocrinology.dk/nbv/diabetes-melitus/behandling-og-kontrol-af-type-2-diabetes/
Hoelzel W, et al. IFCC reference system for measurement of hemoglobin A1c in human blood and the national standardization schemes in the United States, Japan, and Sweden. Clin Chem 2004;50(1):166–174. doi.org/10.1373/clinchem.2003.024802
Nathan DM, et al. Translating the A1C assay into estimated average glucose values. Diabetes Care 2008;31(8):1473–1478. doi.org/10.2337/dc08-0545
CDC: Diabetes testing. www.cdc.gov/diabetes/diabetes-testing/index.html

Keep reading

More free tools

The conversions are arithmetic. The limits say where a number falls; they do not diagnose. Your own targets are set with your doctor or diabetes team.

Keep your HbA1c in one place

The Kairi app logs HbA1c, blood sugar and blood pressure, shows how they move over time, and scores food for your blood sugar.