HbA1c (glycated haemoglobin) is a blood test that measures the average blood sugar level over the past 2–3 months. It is widely used to diagnose diabetes and monitor long-term blood sugar control in people with diabetes. Unlike fasting blood sugar, HbA1c does not require fasting.

HbA1c Report Reader | Diabetes Interpretation Tool

Q: What is a normal HbA1c level?

For non-diabetic adults, a normal HbA1c is below 5.7% (39 mmol/mol). Values between 5.7–6.4% (39–46 mmol/mol) suggest prediabetes, and 6.5% (48 mmol/mol) or above suggests the diabetes range. Always confirm findings with your doctor.

Q: What is the difference between HbA1c % and mmol/mol?

HbA1c % (NGSP/DCCT unit) and mmol/mol (IFCC unit) measure the same thing using different scales. Most laboratories in Sri Lanka report HbA1c as %. European labs commonly use mmol/mol. A value below 20 is almost always in % units; a value of 20 or above is almost always in mmol/mol. Use the unit your laboratory report states.

Q: What is estimated average glucose (eAG)?

Estimated average glucose (eAG) converts your HbA1c result into an approximate average blood sugar level in mg/dL or mmol/L — the same units used on glucose meters. The formula is: eAG (mg/dL) = 28.7 × HbA1c(%) − 46.7. It gives patients a more intuitive understanding of their long-term blood sugar control.

Q: Can a single HbA1c test diagnose diabetes?

In most guidelines, a single HbA1c of 6.5% or above in a person without symptoms requires confirmation with a repeat test. In the presence of clear symptoms of diabetes, a single HbA1c may be sufficient. Your doctor will decide based on the full clinical picture. HbA1c is only one part of diabetes assessment.

Purpose HbA1c Units Date Conditions

Why was this HbA1c test done?

Please select the option that best applies to you. This determines how your result is interpreted.

Have you ever been diagnosed with diabetes, or are you currently taking any form of treatment for diabetes — including medications, diet control, or exercise specifically for blood sugar management?

⚠️ Your result interpretation depends on this information. Any inaccuracy in your response will affect the interpretation.

Enter Your HbA1c Result

Type the number from your laboratory report. The unit will be detected automatically — please confirm it matches your report.

ℹ️ HbA1c results are reported in two units: % (percentage) or mmol/mol (IFCC). Values below 20 are almost always in %. Values of 20 or above are almost always in mmol/mol. Entering the wrong unit will give an incorrect interpretation.

Change unit (if auto-detection is incorrect):

How would you like estimated average glucose displayed?

The estimated average glucose (eAG) is a calculated value from your HbA1c. Choose your preferred unit.

When was this HbA1c test done?

The date of your test helps us flag whether the result is recent enough to reflect your current blood sugar control.

Conditions that may affect HbA1c accuracy

Some medical conditions can cause HbA1c to be falsely high or falsely low. Please tick any that apply to you.

If none of the conditions below apply, select None of the above.

Anaemia / low haemoglobin

Recent blood transfusion

Pregnancy

Kidney disease

Haemoglobin disorder (thalassaemia, sickle cell, etc.)

Recent major bleeding

Recent severe illness

None of the above

Your Result

Your Entered Details

Your HbA1c: =

⚠️ Interpretation based on your reported treatment status

. Please ensure this information is accurate, as any error will affect the result interpretation.

HbA1c Result Interpretation

Estimated Average Blood Sugar (eAG)

Formula: eAG (mg/dL) = 28.7 × HbA1c(%) − 46.7

⚠️ HbA1c Accuracy May Be Affected

Certain medical conditions can cause HbA1c to be falsely high or falsely low, meaning it may not fully reflect your true average blood sugar level. Medical interpretation is recommended.

🤰 Pregnancy Note

HbA1c alone should not be used to diagnose or exclude gestational diabetes during pregnancy. Please consult your doctor for appropriate testing.

ℹ️ Important

HbA1c alone does not diagnose diabetic emergencies. Seek urgent medical care if you experience vomiting, dehydration, severe weakness, difficulty breathing, confusion, abdominal pain, or very high current blood sugar readings.

This tool provides educational interpretation only and does not replace medical advice, diagnosis or treatment. Always consult your doctor for personalised guidance.

Understanding Your HbA1c Result

HbA1c (glycated haemoglobin) reflects your average blood sugar over the past 2–3 months. Unlike fasting blood sugar, it does not require fasting and is not affected by a single meal. It is one of the most important tests for diagnosing and monitoring diabetes.

HbA1c Reference Table — Diabetes Screening (Non-Diabetic Adults)

HbA1c (%)	HbA1c (mmol/mol)	Category	What it means
Below 5.7%	Below 39	Usually Normal	Blood sugar control is generally within the normal range.
5.7 – 6.4%	39 – 46	Prediabetes Range	Higher than normal. Increased future risk of diabetes. Lifestyle changes recommended.
6.5% or above	48 or above	Diabetes Range	Consistent with diabetes range. Medical confirmation and assessment needed.

HbA1c Reference Table — Diabetes Monitoring (Known Diabetic Patients)

HbA1c (%)	HbA1c (mmol/mol)	Control Category	What it means
Below 7%	Below 53	Often Good Control	Often considered acceptable diabetes control for many patients.
7 – 8.9%	53 – 74	Moderate / Suboptimal	Blood sugar control could be improved. Review with your doctor.
9 – 9.9%	75 – 85	Poor Control	Diabetes is poorly controlled. Medical review recommended.
10% or above	86 or above	Very Poor Control	Very poor long-term control. Increased risk of complications. Urgent medical review recommended.

What is Estimated Average Glucose (eAG)?

Estimated average glucose (eAG) converts your HbA1c into an approximate daily average blood sugar in mg/dL or mmol/L — the same units displayed on glucose meters. The formula is: eAG (mg/dL) = 28.7 × HbA1c(%) − 46.7. For example, an HbA1c of 7% corresponds to an eAG of approximately 154 mg/dL (8.6 mmol/L).

What Can Affect HbA1c Accuracy?

Certain conditions can cause HbA1c to be falsely high or falsely low, making it less reliable as a measure of true blood sugar control:

🩸 Anaemia / low haemoglobin
🏥 Recent blood transfusion
🤰 Pregnancy
🫘 Kidney disease
🧬 Thalassaemia or haemoglobin disorders
🩹 Recent major bleeding
🤒 Recent severe illness

If any of these apply, your HbA1c result should be interpreted with caution. Your doctor may recommend alternative blood sugar tests such as fasting blood sugar (FBS) or post-meal blood sugar (PPBS).

HbA1c % vs mmol/mol

Most Sri Lankan laboratories report HbA1c as a percentage (%). European laboratories commonly use mmol/mol (IFCC units). Both measure the same thing on different scales. Values below 20 are almost always in %; values of 20 or above are almost always in mmol/mol. This tool auto-detects the unit based on your entered value — always confirm this matches your lab report.

Frequently Asked Questions About HbA1c

Common questions about HbA1c, diabetes interpretation, and estimated average glucose — answered by Sineth Hospitals.

What is HbA1c? ▼

HbA1c (glycated haemoglobin) is a blood test that measures the average blood sugar level over the past 2–3 months. When blood sugar is high, more glucose attaches to haemoglobin in red blood cells — this percentage is measured as HbA1c. It does not require fasting and is unaffected by a single meal, making it a reliable long-term indicator of blood sugar control.

What is a normal HbA1c level? ▼

For non-diabetic adults, a normal HbA1c is generally below 5.7% (39 mmol/mol). Values between 5.7–6.4% (39–46 mmol/mol) fall in the prediabetes range, and 6.5% (48 mmol/mol) or above is consistent with the diabetes range. However, these are reference ranges and not absolute diagnostic cut-offs — always consult your doctor for a proper assessment.

What HbA1c level means diabetes? ▼

An HbA1c of 6.5% (48 mmol/mol) or above is consistent with the diabetes range. In most guidelines, diagnosis requires confirmation with a repeat HbA1c or another blood sugar test on a different day (unless clear symptoms are present). A single result alone is usually not sufficient for diagnosis. Your doctor will decide based on your full clinical picture.

What is the difference between HbA1c % and mmol/mol? ▼

Both measure the same thing using different units. HbA1c % (NGSP/DCCT scale) is the older and more widely used unit in Sri Lanka and the USA. HbA1c mmol/mol (IFCC scale) is used by many European laboratories. Values below 20 are almost always in %; values of 20 or above are almost always in mmol/mol. If unsure, check your laboratory report for the unit label.

What is estimated average glucose (eAG)? ▼

Estimated average glucose (eAG) converts your HbA1c into a daily average blood sugar in mg/dL or mmol/L. This helps patients relate their HbA1c to the numbers they see on their glucose meter. The formula is: eAG (mg/dL) = 28.7 × HbA1c(%) − 46.7. For example, an HbA1c of 7% equals an eAG of about 154 mg/dL. It is an estimate — actual daily readings will vary.

Can a single HbA1c test diagnose diabetes? ▼

In most clinical guidelines, a single HbA1c of 6.5% or above in a person without symptoms of diabetes should be confirmed with a repeat test before a diagnosis is made. In the presence of clear diabetes symptoms (excessive thirst, frequent urination, unexplained weight loss), a single elevated HbA1c together with clinical findings may be sufficient. HbA1c is one part of diabetes assessment — consult your doctor for a proper evaluation.

HbA1c Report Reader & Diabetes Interpretation Tool