How do you convert A1C to average blood glucose?

Use the American Diabetes Association formula from the ADAG study: estimated average glucose (eAG) in mg/dL = 28.7 × A1C − 46.7. For mmol/L, eAG = 1.59 × A1C − 2.59. For example, an A1C of 7% works out to an eAG of about 154 mg/dL (8.6 mmol/L). This free converter does the math in both directions.

eAG stands for estimated Average Glucose. It expresses your A1C (a 2–3 month average of blood sugar) in the same mg/dL or mmol/L units you see on a glucose meter, so the number is easier to relate to day-to-day readings. It is a calculated estimate, not a direct measurement.

What is a normal A1C level?

By ADA criteria, an A1C below 5.7% is in the normal range, 5.7%–6.4% indicates prediabetes, and 6.5% or higher indicates diabetes (on a confirmed test). Diagnosis and targets are set by your doctor — this tool only converts numbers and is not medical advice.

Is the A1C converter free?

Yes — 100% free. Everything is calculated privately in your browser; nothing is stored or sold. It is an informational converter, not medical advice.

A1C ↔ Average Glucose Converter

Convert HbA1c to estimated average glucose (eAG) — and back — using the ADA / ADAG formula.

A1C / HbA1c (%)

Typical range 4–14%.

Estimated average glucose

—

eAG

A1C ↔ Average Glucose Converter — guide

Informational converter — not medical advice. This tool only translates between A1C and estimated average glucose using a published formula. It does not diagnose, set targets, or replace your lab results or your doctor. Discuss your numbers with your healthcare provider.

What it does

Your A1C (also written HbA1c) reflects your average blood sugar over the previous 2–3 months as a percentage. A glucose meter or CGM, on the other hand, reads in mg/dL (US) or mmol/L. This converter puts both on the same scale by computing your estimated average glucose (eAG) — so a "7% A1C" becomes a number you can compare to your daily readings — and converts in reverse too.

The formula it uses

The conversion comes from the A1C-Derived Average Glucose (ADAG) study (Nathan et al., 2008), the basis for the American Diabetes Association's eAG:

eAG (mg/dL) = 28.7 × A1C − 46.7
eAG (mmol/L) = 1.59 × A1C − 2.59
Reverse: A1C (%) = (eAG mg/dL + 46.7) / 28.7

Worked example

An A1C of 7.0%:

28.7 × 7.0 − 46.7 = 200.9 − 46.7 = 154 mg/dL.
In mmol/L: 1.59 × 7.0 − 2.59 = 11.13 − 2.59 = 8.5 mmol/L (≈ 154 ÷ 18.0).
By ADA criteria 7.0% is in the diabetes range, so the badge reads Diabetes range.

Reverse check: an average glucose of 154 mg/dL → (154 + 46.7) / 28.7 = 7.0% A1C.

ADA reference ranges (A1C)

A1C	Category	Approx. eAG
Below 5.7%	Normal	< 117 mg/dL
5.7% – 6.4%	Prediabetes	117 – 137 mg/dL
6.5% and above	Diabetes	≥ 140 mg/dL

Categories shown for context only; diagnosis requires a confirmed test interpreted by a clinician.

How to use it

Choose a direction — A1C to glucose, or glucose to A1C.
Enter your A1C %, or your average glucose and its units.
Read the converted value, both unit systems, and the ADA category, then Copy result or Copy share link.

Accuracy notes

eAG is an estimate. The ADAG regression has scatter — two people with the same A1C can have somewhat different true averages. Conditions affecting red blood cells (anemia, recent transfusion, some hemoglobin variants, pregnancy) can make A1C less reliable.
mg/dL ↔ mmol/L within glucose uses the standard factor 18.0182.
Calculated client-side — nothing you enter is transmitted or stored.

How to embed this tool on your website

No account, no coding. Copy the embed code and paste it where you want it to appear:

<iframe src="https://snaptoolsuite.com/a1c-average-glucose-converter/?embed=1"
  style="width:100%;max-width:560px;height:680px;border:0;"
  title="A1C to Average Glucose Converter" loading="lazy"></iframe>
<p>Free <a href="https://snaptoolsuite.com/a1c-average-glucose-converter/">A1C to Average Glucose Converter</a> by Snap Tool Suite</p>

2 Paste it on your page

3 It just works

Frequently asked questions

How do you convert A1C to average glucose?

Use the ADA/ADAG formula: eAG (mg/dL) = 28.7 × A1C − 46.7; eAG (mmol/L) = 1.59 × A1C − 2.59. A 7% A1C is about 154 mg/dL (8.5 mmol/L).

What is eAG?

Estimated Average Glucose — your A1C expressed in the mg/dL or mmol/L units you see on a meter, so it's easier to relate to daily readings. It's a calculated estimate, not a direct reading.

What is a normal A1C?

By ADA criteria: below 5.7% normal, 5.7–6.4% prediabetes, 6.5%+ diabetes on a confirmed test. Your doctor sets diagnosis and targets.

Is it really free?

Yes. 100% free, everything runs in your browser. Informational only — not medical advice.

Related tools

Add this converter to your site

Free to embed on any website, blog, or clinic page. One line of HTML — no account, no code, no cost.

<iframe src="https://snaptoolsuite.com/a1c-average-glucose-converter/?embed=1"
  style="width:100%;max-width:560px;height:680px;border:0;"
  title="A1C to Average Glucose Converter" loading="lazy"></iframe>

2 Paste it on your page

3 It just works

Everything is calculated in your browser. We don't store or sell your data. Informational converter — not medical advice.