A1c and average glucose

About this calculator

Enter an A1c result to see the estimated average blood sugar it matches over the past two to three months, using the ADAG study equation.

What you need

• Your A1c result, as a percentage

How it is calculated

Estimated average glucose (mg/dL) = 28.7 × A1c − 46.7, from the A1c-Derived Average Glucose (ADAG) study. mmol/L = mg/dL ÷ 18. IFCC A1c (mmol/mol) = (A1c % − 2.15) × 10.929. Diagnostic ranges: under 5.7%, 5.7% to 6.4% (prediabetes) and 6.5% or above (diabetes).

What the result can and cannot tell you

The ranges shown are the A1c levels used for diagnosis. A diagnosis needs confirmation by your doctor, and if you already have diabetes, your A1c target is set with your care team. Keeping blood sugar in range lowers the risk of diabetic eye disease, and people with diabetes need regular dilated eye exams.

References

1. Nathan and colleagues: Translating the A1C assay into estimated average glucose values. Diabetes Care 2008
2. CDC: A1C test for diabetes and prediabetes
3. Netra Eye Institute: Diabetic retinopathy

Related

• Blood pressure category
• Nighttime blood pressure dip
• Diabetic retinopathy guide
• All eye calculators

For information only. These tools explain numbers and do not replace an eye examination or your eye doctor’s advice. Values you enter stay in your browser.