Normal Blood Sugar Levels by Age: Complete Chart & Guide

Normal Blood Sugar Levels by Age: Chart and Guide

Normal blood sugar levels do not have completely different healthy ranges for every age. For most nonpregnant people without diabetes, a fasting plasma glucose of 99 mg/dL (5.5 mmol/L) or lower is considered normal.

Age becomes more important when healthcare professionals set treatment targets for people who already have diabetes, especially for children, older adults, and pregnant people.

What Are Normal Blood Sugar Levels by Age?

The chart below separates normal diagnostic ranges from diabetes treatment targets so the numbers are easier to understand.

Group	Fasting / Before Meals	After Meals	A1C
People without diabetes	≤99 mg/dL (≤5.5 mmol/L)	≤139 mg/dL (≤7.7 mmol/L) on 2-hour OGTT	<5.7%
Adults with diabetes	80–130 mg/dL (4.4–7.2 mmol/L)	<180 mg/dL (<10.0 mmol/L)	Usually <7%
Healthy older adults with diabetes	80–130 mg/dL	Individualized	<7.0–7.5%
Older adults with complex health needs	90–150 mg/dL	Individualized	<8%
Pregnancy with diabetes	70–95 mg/dL	110 to 140 mg/dL (1 hour after); 100 to 120 mg/dL (2 hours after)	Individualized
Children and teens with diabetes	Individualized	Individualized	Usually <7%

Important: The rows for diabetes are treatment goals, not universal “normal” levels.

Do Normal Blood Sugar Levels Really Change With Age?

Not significantly for diagnosis.

For nonpregnant people without diabetes, the same general thresholds are used to identify normal glucose, prediabetes, and diabetes.

What changes more with age is the recommended treatment target for someone who already has diabetes.

Older adults, for example, may need less aggressive glucose targets if they have multiple health conditions, cognitive impairment, frailty, or a high risk of low blood sugar.

What Is Normal Blood Sugar for People Without Diabetes?

For people without diabetes, the main laboratory reference ranges are:

Fasting glucose: 99 mg/dL or below
2-hour glucose tolerance result: 139 mg/dL or below
A1C: below 5.7%

These values are commonly used to distinguish normal glucose from prediabetes and diabetes.

What Are Blood Sugar Targets for Adults With Diabetes?

For many nonpregnant adults with diabetes, common treatment targets are:

Before meals: 80–130 mg/dL
Peak after meals: below 180 mg/dL
A1C: below 7%

These targets are individualized based on overall health, medications, hypoglycemia risk, and personal treatment goals.

What Are Blood Sugar Targets for Children and Teens With Diabetes?

Blood sugar goals for children and teenagers are individualized, but an A1C below 7% is a common general target.

Healthcare professionals may adjust goals based on:

Age
Hypoglycemia risk
Type of diabetes
Insulin use
Monitoring technology
Daily routine

Children should not simply be given adult targets without clinical guidance.

What Are Blood Sugar Targets for Adults Over 65?

Older adults with diabetes may need different targets depending on their health.

Health status	Fasting / Premeal Goal	A1C Goal
Healthy older adult	80–130 mg/dL	<7.0–7.5%
Complex/intermediate health	90–150 mg/dL	<8.0%
Very complex/poor health	100–180 mg/dL	Avoid strict A1C dependence

The goal is to balance glucose control with safety, especially the risk of hypoglycemia.

What Are Blood Sugar Targets During Pregnancy?

Pregnancy uses different glucose targets.

Common goals for people with diabetes during pregnancy include:

Fasting: 70–95 mg/dL
1 hour after meals: 110–140 mg/dL
2 hours after meals: 100–120 mg/dL

Pregnancy glucose management should always be guided by a healthcare professional.

What Do Fasting, After-Meal, and A1C Results Mean?

These tests measure different parts of blood sugar control.

Test	Normal	Prediabetes	Diabetes
Fasting glucose	≤99 mg/dL	100–125 mg/dL	≥126 mg/dL
A1C	<5.7%	5.7–6.4%	≥6.5%
2-hour OGTT	≤139 mg/dL	140–199 mg/dL	≥200 mg/dL

A single abnormal result does not always confirm diabetes. Testing may need to be repeated.

What Is Time in Range?

Time in Range (TIR) shows how much of the day a person’s glucose stays within a target range.

For many adults with diabetes who use a continuous glucose monitor, a common target range is:

70–180 mg/dL

A common goal is to remain in this range for more than 70% of the day.

Time in Range can give a more detailed picture than A1C alone because it shows daily glucose highs and lows.

What Factors Can Affect Blood Sugar Levels?

Blood sugar can change throughout the day for many reasons.

Common factors include:

Food and carbohydrate intake
Exercise
Stress
Illness
Sleep
Medications
Insulin
Hormonal changes
Pregnancy
Alcohol
Dehydration

That is why one isolated glucose reading should be interpreted in context.

When Is Blood Sugar Too Low?

Blood sugar below 70 mg/dL (3.9 mmol/L) is generally considered low for people with diabetes.

Symptoms may include:

Shaking
Sweating
Hunger
Dizziness
Weakness
Confusion
Fast heartbeat

Severe hypoglycemia can cause seizures or loss of consciousness and requires urgent treatment.

When Is Blood Sugar Too High?

High blood sugar becomes more concerning when readings are repeatedly above the recommended range or are accompanied by symptoms.

Possible symptoms include:

Excessive thirst
Frequent urination
Fatigue
Blurred vision
Headache
Unexplained weight loss

Repeated fasting glucose of 126 mg/dL or higher falls within the diabetes range and should be medically evaluated.

When Should You Talk to a Doctor About Your Blood Sugar?

Talk to a healthcare professional if your glucose readings are repeatedly outside the normal range or if you have symptoms of high or low blood sugar.

Testing is particularly important if you have: