HbA1c and Blood Sugar Levels Explained (Normal Ranges)

HbA1c shows your average blood sugar over roughly the past three months. Below 5.7% is the normal range, 5.7–6.4% is the prediabetes range, and 6.5% or higher is the diabetes range. A fasting glucose of 70–99 mg/dL is typical, 100–125 is the prediabetes range, and 126 or more on two tests is the diabetes range.

You can check your own numbers with the free HbA1c & Blood Sugar Checker. It shows which range each result falls in and converts between units. Nothing you enter leaves your browser.

What does HbA1c measure?

Sugar in your blood sticks to hemoglobin, the protein inside red blood cells. Red cells live for about three months, so the share of hemoglobin carrying sugar, the HbA1c, reflects your average blood sugar over that time. It doesn't change much from one day to the next, which is why it doesn't need fasting.

HbA1c is reported as a percentage (common in the US and South Asia) or in mmol/mol (UK and much of Europe). The checker accepts both.

HbA1c ranges

HbA1c (%)	HbA1c (mmol/mol)	Range
Below 5.7	Below 39	Normal
5.7 to 6.4	39 to 47	Prediabetes range
6.5 or higher	48 or higher	Diabetes range

For people who already have diabetes, many treatment plans aim for an HbA1c under 7% (53 mmol/mol), but your own target depends on your age, health and medicines, so agree it with your doctor.

Fasting, post-meal and random glucose

Glucose tests measure the sugar in your blood at the moment of the test.

Test	Normal	Prediabetes range	Diabetes range
Fasting (8+ hours, no food)	70–99 mg/dL (3.9–5.5 mmol/L)	100–125 mg/dL (5.6–6.9 mmol/L)	126+ mg/dL (7.0+ mmol/L)
2 hours after a glucose drink	Below 140 mg/dL (7.8 mmol/L)	140–199 mg/dL (7.8–11.0 mmol/L)	200+ mg/dL (11.1+ mmol/L)
Random (any time)	Usually below 140 mg/dL		200+ mg/dL with symptoms

If a sample marked "random" was actually taken fasting, the fasting ranges apply, so tell the checker which test it was. To convert, divide mg/dL by 18 to get mmol/L.

How do I check my results?

1. Open the HbA1c & Blood Sugar Checker. It opens on the blood sugar group.
2. Choose Enter values and type your HbA1c and glucose results with their units, or use Paste report or Upload PDF with a digital lab report.
3. Read each result's range, what it means and the questions worth asking your doctor.
4. Use Copy summary to save it.

What can make HbA1c misleading?

HbA1c relies on normal red blood cells. It can read falsely low or high with anaemia, recent blood loss or transfusion, pregnancy, kidney disease and some inherited hemoglobin variants (such as sickle cell trait or thalassaemia). If your HbA1c and glucose results don't match, your doctor may use a different test.

Fasting glucose can be raised by stress, illness, a late meal, some medicines (such as steroids) and poor sleep. One high reading is a reason for a repeat test, not panic.

What should I do if I'm in the prediabetes range?

Prediabetes is common and often reversible. The steps with the best evidence are steady weight loss if you're overweight (even 5–7% of body weight helps), about 150 minutes of brisk activity a week, and a diet with more fibre and fewer refined carbs and sugary drinks. Our Diabetes Diet Plan builds a 7-day meal plan with desi or Western food, and the Food Calorie & Fiber Checker shows how your day adds up.

When is blood sugar an emergency?

Glucose below 54 mg/dL (3.0 mmol/L) is significantly low. Signs include shaking, sweating, confusion and a fast heartbeat; take fast-acting sugar and get help. Very high readings with vomiting, deep breathing, extreme thirst or drowsiness need emergency care, as they can signal ketoacidosis.

These ranges are for non-pregnant adults. Pregnancy uses lower targets; see your care team. When you have your numbers, check them here, and see how to read a full blood test report.