Official ADAG Formula (NICE & ADA)

HbA1c to Blood Glucose Calculator

Translate your 3-month HbA1c percentage and IFCC value (mmol/mol) into estimated average glucose in mmol/L and mg/dL using the validated ADAG trial formula.

HbA1c to Glucose Calculator

Free, clinical-grade reference tools that explain blood pressure, blood glucose, and HbA1c numbers in plain words for adults and seniors.

HbA1c (%)

Normal is below 5.7%

IFCC (mmol/mol)

mmol/mol

Official IFCC standard

Estimated Average Glucose (mg/dL)

mg/dL

US standard

Estimated Average Glucose (mmol/L)

mmol/L

Standard

ADA Clinical InterpretationDiabetes

An HbA1c of 6.5% (48 mmol/mol) or greater on two separate tests confirms diabetes.

Recommended Action: Work closely with your GP to establish an individualised HbA1c target, adjust nutrition, and evaluate medication if necessary.

Official ADAG Clinical Formula:

eAG (mmol/L) = 1.59 × A1C − 2.59(Nathan DM et al., A1C-Derived Average Glucose Study, Diabetes Care 2008)

What is HbA1c and Estimated Average Glucose?

HbA1c measures the percentage of your red blood cells glycated with glucose over their 2-to-3-month lifespan. The ADAG study established the mathematical relationship translating this into everyday blood glucose values.

How to Use This Converter

Enter your lab HbA1c result to see what daily blood glucose level it reflects, or enter your average home monitor reading to estimate your upcoming HbA1c result.

Recommended HbA1c Clinical Targets (NICE & ADA Standards)

Healthy Adults without Diabetes Below 5.7% (< 39 mmol/mol) Normal physiological range.

Prediabetes Window 5.7% – 6.4% (39–46 mmol/mol) Actionable lifestyle intervention zone to prevent progression.

Most Adults with Diabetes < 7.0% (< 53 mmol/mol) / 48 mmol/mol NICE Standard clinical target to minimise microvascular complications.

Seniors or Adults with Comorbidities < 7.5% – 8.0% (< 58–64 mmol/mol) Relaxed target to protect against dangerous hypoglycaemia.