How do you calculate A1C from average blood sugar?

Use the reverse ADAG formula: A1C = (Average Glucose in mg/dL + 46.7) ÷ 28.7. For example, an average glucose of 154 mg/dL gives: (154 + 46.7) ÷ 28.7 = 7.0% A1C.

What does A1C stand for?

A1C stands for Hemoglobin A1C (also written HbA1c). The 'A1C' refers to a specific type of glycated hemoglobin where glucose binds to the hemoglobin in your red blood cells.

What A1C level is considered diabetic?

An A1C of 6.5% or higher is the diagnostic threshold for diabetes according to the American Diabetes Association. This corresponds to an average blood sugar of about 140 mg/dL.

Is fasting required for an A1C test?

No, fasting is not required for an A1C test. Since it measures your average blood sugar over 2-3 months, a single meal won't affect the result.

Why is my A1C higher than my meter readings?

Your meter captures point-in-time readings (often before meals when blood sugar is lower), while A1C reflects all 24 hours including after-meal spikes. Also, the A1C formula is weighted toward more recent glucose levels.

What is eAG (estimated average glucose)?

eAG (estimated Average Glucose) is your average blood sugar level in mg/dL or mmol/L, calculated from your A1C using the ADAG formula. It helps you understand what your A1C means in everyday blood sugar terms.

Can I lower my A1C naturally?

Yes, lifestyle changes can lower A1C: balanced diet, regular exercise, weight management, stress reduction, and adequate sleep. A 1-point reduction in A1C significantly reduces diabetes complications.

What is the ADAG formula?

The ADAG (A1C-Derived Average Glucose) formula is: eAG (mg/dL) = 28.7 × A1C − 46.7. It was established by a major study published in Diabetes Care in 2008 and is endorsed by the ADA.

Can anemia affect A1C results?

Yes, certain conditions can affect A1C accuracy including anemia, hemoglobin variants, recent blood transfusions, pregnancy, and kidney or liver disease. In these cases, consult your healthcare provider for alternative tests.

How often should I get my A1C tested?

The ADA recommends A1C testing at least twice a year if meeting treatment goals, or quarterly if treatment has changed or you're not meeting targets.

What is the difference between A1C and blood glucose?

Blood glucose is a snapshot of your blood sugar at one moment in time. A1C is a 3-month average. Daily glucose readings vary widely throughout the day, while A1C provides a stable measure of overall control.

Health

A1C Calculator

Calculate A1C and average blood sugar with the ADAG formula. See your diabetes risk category and eAG in mg/dL or mmol/L instantly.

Medical Disclaimer

This calculator is for educational purposes only and should not replace professional medical advice. Always consult your healthcare provider for A1C testing and diabetes management.

Conversion Mode

A1C Level

Glucose Unit

Made with love

Support

Related Calculators

You might also find these calculators useful

BMI Calculator

Calculate your Body Mass Index

Calorie Calculator

Calculate daily calorie needs

Macro Calculator

Calculate your daily macronutrient needs

TDEE Calculator

Calculate your Total Daily Energy Expenditure

How to Calculate A1C and Average Blood Sugar

The A1C test (also called HbA1c or hemoglobin A1C) measures your average blood sugar over the past 2-3 months. This calculator helps you convert between A1C percentage and estimated average glucose (eAG) using the ADAG formula. Whether you're tracking diabetes management, monitoring prediabetes, or simply curious about your blood sugar trends, understanding your A1C is essential for long-term health.

What Is A1C (Hemoglobin A1C)?

A1C, short for hemoglobin A1C (HbA1c), measures the percentage of your red blood cells that have glucose attached to them. Since red blood cells live for about 3 months, A1C provides a picture of your average blood sugar levels over that period. Unlike daily finger-stick readings that capture a single moment, A1C shows the bigger picture of your glucose control.

ADAG Formula

eAG (mg/dL) = 28.7 × A1C − 46.7

Why Use This A1C Calculator?

Bi-directional Conversion

Convert A1C to average glucose OR average glucose to estimated A1C.

Instant Category Assessment

See immediately if you're in normal, prediabetes, or diabetes range.

Step-by-step Formula

Understand the ADAG calculation process with detailed math steps.

Multiple Units

Switch between mg/dL (US) and mmol/L (international) glucose units.

Medical-grade Formula

Uses the official ADA-endorsed ADAG equation from peer-reviewed research.

Visual Status Indicator

Color-coded gauge shows exactly where your A1C falls in the health spectrum.

How to Use This A1C Calculator

When to Use This A1C Calculator

Diabetes Management

Track your A1C progress between lab tests and understand what your results mean.

Pre-diabetes Monitoring

Understand your risk level and set targets for lifestyle changes.

CGM Users

Compare your continuous glucose monitor averages to estimated A1C.

Medical Preparation

Estimate your A1C before doctor visits to prepare questions.

International Conversion

Convert between mg/dL (US) and mmol/L (international) units easily.

Healthcare Education

Learn the ADAG formula and understand how A1C relates to daily blood sugar.

Frequently Asked Questions

A normal A1C is below 5.7%. This indicates healthy blood sugar control. Between 5.7% and 6.4% is considered prediabetes, and 6.5% or higher indicates diabetes.

How to Calculate A1C and Average Blood Sugar

What Is A1C (Hemoglobin A1C)?

ADAG Formula

eAG (mg/dL) = 28.7 × A1C − 46.7