A1C Calculator

A1C to estimated average glucose

A1C Calculator: Turn Results into Actionable Daily Decisions

Convert your A1C to estimated average glucose instantly, compare it with CGM patterns, and use the result to plan the next step in care.

A1C conversion tool

Enter your A1C

%

Accepted range: 4.0% to 15.0%

Common values

Result unit

Your estimated result

eAG

Estimated Average Glucose

154mg/dL

A1C screening range

Diabetes

This estimate helps compare A1C with daily glucose units. It does not replace a laboratory result or diagnosis.

ADAG Study Standard

Our calculations use the ADAG (A1C-Derived Average Glucose) formula validated by the American Diabetes Association and the EASD. The formula is: **eAG (mg/dL) = 28.7 × A1C − 46.7**.
01

Published Formulas

Each calculator identifies its equation, required input, output unit, and practical limitations.

02

Fast Comparison

Check A1C, eAG, GMI, and Time in Range without jumping between multiple tools.

03

Clear Boundaries

Calculated estimates are separated from laboratory results, diagnosis, and treatment decisions.

Understanding the result

A1C, eAG, GMI, and TIR Are Not the Same Metric

The numbers are related, but each begins with a different source and answers a different question. Keep the metric name and unit attached to every result.

Explore All Calculators
% or mmol/mol

A1C

Laboratory blood test

Longer-term glucose exposure

mg/dL or mmol/L

eAG

Calculated from A1C

A1C expressed as estimated glucose

%

GMI

CGM mean glucose

CGM-derived glucose indicator

% or time/day

Time in Range

CGM readings

Time within stated glucose limits

Common conversions

A1C Calculator Quick Conversion Examples

View complete A1C conversion chart
Common A1C values converted to estimated average glucose
A1CeAG (mg/dL)eAG (mmol/L)
5.0%975.4
5.7%1176.5
6.5%1407.8
7.0%1548.6
8.0%18310.2

Before calculating

Common A1C Calculator Mistakes

Most incorrect results start with the wrong metric or unit—not difficult arithmetic. Check these four points before using an output.

01

A single reading is not an average

Do not enter fasting glucose, a current meter value, or one CGM reading into a field that asks for mean glucose.

02

mmol/mol is not mmol/L

HbA1c uses mmol/mol internationally. Glucose concentration uses mmol/L; the two units cannot be swapped.

03

GMI is not laboratory A1C

GMI comes from CGM mean glucose and may differ from an A1C measured from a blood sample.

04

A screening range is not a personal target

Diagnosis, confirmation, and an individual management goal are separate clinical questions.

Reader feedback

What People Say About the Calculator

Comments shared by people using our A1C conversion tools.

DM

Using this tool is so simple. It translates my A1C results into numbers that actually make sense for my day-to-day blood sugar tracking.

David M.

Boston, MA

From the A1C learning center

Latest A1C Articles

Costs & Coverage
Article

A1C Test Cost Without Insurance

A1C test prices without insurance, from lab chains to pharmacies to at-home kits. Where the cheapest options are and how to avoid surprise billing.

Read article
Diabetes Mysteries
Article

Low A1C but High Blood Sugar: Causes, Meaning & What to Do

A low A1C alongside high readings points to shortened red blood cell survival or a test artifact. The causes, and which follow-up tests to request.

Read article
Costs & Coverage
Article

Walmart A1C Test: Review & Cost

What Walmart's A1C test costs, how accurate the at-home kits are, how to read your result, and when a proper lab test is worth paying for instead.

Read article
Diet & Nutrition
Article

Apple Cider Vinegar and A1C

Vinegar can modestly blunt post-meal glucose spikes, but the effect is small and short-lived. What the studies found, and a realistic expectation.

Read article
Lifestyle
Article

Alcohol and A1C: The Hidden Impact

Alcohol moves blood sugar in both directions and can cause delayed lows hours later. What each drink does, and the safe limits worth knowing.

Read article
Diet & Nutrition
Article

Sugar Substitutes and A1C

Which sweeteners raise blood sugar and which do not. Stevia, erythritol, sucralose and aspartame compared, plus what the gut-microbiome research shows.

Read article
Stress & Mental Health
Article

Can Stress Increase Your A1C Level?

Yes, and the mechanism is cortisol rather than eating habits. How much stress can move your A1C, how fast, and how to tell if it is the cause.

Read article
Diet & Nutrition
Article

Intermittent Fasting and A1C

Fasting can lower A1C for some people and cause dangerous lows for others. Who it suits, which protocols have evidence, and the medication warnings.

Read article
Common Questions

Everything you need to know about A1C Testing

An A1C calculator converts a laboratory A1C percentage into estimated average glucose (eAG). It helps express a longer-term A1C result in the same mg/dL or mmol/L units commonly used by glucose meters and CGM reports.