Blood Sugar Chart: Normal and Diabetic Ranges

This blood sugar chart shows normal blood glucose levels before and after meals, and recommended A1C levels for people with and without diabetes. All values are based on the 2026 American Diabetes Association Standards of Medical Care in Diabetes.

Blood Sugar Chart — ADA 2026 Guidelines
Test / Timing Normal (No Diabetes) Prediabetes ADA Target (With Diabetes)
Fasting Blood Sugar (8+ hours without food)
mg/dL70–99 mg/dL100–125 mg/dL80–130 mg/dL
mmol/L3.9–5.5 mmol/L5.6–6.9 mmol/L4.4–7.2 mmol/L
1–2 Hours After Meals (Postprandial)
mg/dL<140 mg/dL140–199 mg/dL<180 mg/dL
mmol/L<7.8 mmol/L7.8–11.0 mmol/L<10.0 mmol/L
A1C (3-month average)
A1C %<5.7%5.7–6.4%<7.0%
eAG equivalent<117 mg/dL117–137 mg/dL<154 mg/dL

Source: American Diabetes Association Standards of Medical Care in Diabetes — 2026. Individual targets may vary. Always consult your healthcare provider.

Fasting blood glucose — visual range (mg/dL)
ADA 2026
<7099125180250+
Low (<70)
Normal (70–99)
Prediabetes (100–125)
Diabetes (126+)
Danger zone
Key Points

Regular monitoring of fasting, after-meal, and A1C levels helps assess blood sugar management and overall health. The A1C test reflects average blood sugar over 2–3 months and is the most important long-term measure for people with diabetes.

Blood sugar targets may need to be individualised based on age, duration of diabetes, other health conditions, and hypoglycaemia risk. Always discuss your specific targets with your healthcare provider.

Fasting Blood Sugar

A fasting blood sugar (fasting plasma glucose or FPG) is measured after fasting — not eating or drinking anything except water — for at least 8 hours. It is the most common test used to screen for prediabetes and diabetes.

Fasting tests are performed at a doctor's office or laboratory — a blood sample is drawn from a vein, or collected via a finger-stick with a lancet. Home glucose meters are not appropriate for diagnosis — laboratory standards are more precise. If you suspect diabetes, see a doctor for a formal laboratory test rather than relying on a home meter reading.

Normal fasting blood sugar (no diabetes)

A normal fasting blood glucose for someone without diabetes is 70 to 99 mg/dL (3.9 to 5.5 mmol/L). The ADA recommends routine type 2 diabetes screening starting at age 35, repeated every 3 years if normal. Earlier and more frequent screening is recommended if you have risk factors including obesity, a family history of type 2 diabetes, a history of gestational diabetes, or being of African American, Latino, Asian American, Pacific Islander, or Native American descent.

Prediabetes fasting range

A fasting blood sugar of 100 to 125 mg/dL (5.6 to 6.9 mmol/L) indicates prediabetes. This is a risk factor for type 2 diabetes, heart disease, and stroke, but it is often reversible through lifestyle changes. Children and adolescents with obesity and additional risk factors should be tested beginning at age 10 or at the onset of puberty, whichever comes first.

Random blood glucose test

A random blood glucose test is taken at any time of day, regardless of when you last ate. A result below 140 mg/dL is generally considered normal. A result of 200 mg/dL or above, combined with symptoms of diabetes, is diagnostic of diabetes. Random testing is useful in clinical settings when a fasting test isn't practical, but fasting or A1C tests are preferred for routine screening.

ADA fasting target for people with diabetes

The ADA recommends a fasting blood sugar target of 80 to 130 mg/dL (4.4 to 7.2 mmol/L) for most non-pregnant adults with diabetes. This target may need to be individualised based on age, life expectancy, other health conditions, and hypoglycaemia risk.

After-Meal Blood Sugar (Postprandial)

Blood sugar naturally rises after eating and typically peaks within 1 to 2 hours after the start of a meal before returning toward baseline.

Normal after-meal blood sugar (no diabetes)

A normal blood sugar at 2 hours after eating is below 140 mg/dL (7.8 mmol/L). Healthy adults have been shown to remain below 140 mg/dL about 95–99% of the time. A result of 140–199 mg/dL suggests prediabetes; 200 mg/dL or above may indicate diabetes.

ADA after-meal target for people with diabetes

The ADA recommends blood sugar less than 180 mg/dL (10.0 mmol/L) at 1 to 2 hours after the start of a meal. This is typically the peak reading for people with diabetes. Post-meal monitoring is especially important for people on insulin.

What causes post-meal spikes?

Post-meal glucose rises are influenced by the type and quantity of carbohydrates eaten, glycaemic index, portion size, medication timing, physical activity level, stress, illness, and sleep quality. A registered dietitian can help you identify patterns and adjust your eating habits to manage post-meal levels. See our article on managing high blood glucose after meals →

A1C (HbA1c) Levels

The A1C test — also called HbA1c, haemoglobin A1C, or glycated haemoglobin — measures average blood glucose over the past 2 to 3 months. No fasting is required. Results are reported as a percentage: the higher the percentage, the higher the average blood glucose.

The A1C test may be less accurate for people with certain anaemias or haemoglobin variants, or those receiving treatment for HIV. People of African, Mediterranean, or Southeast Asian descent may also have variants that affect the test.

Normal A1C (no diabetes)

A normal A1C is below 5.7%. Adults over 45 — or younger adults who are overweight with one or more diabetes risk factors — should have a baseline A1C checked and retested every 3 years if normal.

Prediabetes A1C range

An A1C of 5.7% to 6.4% indicates prediabetes. If your result falls in this range, the ADA recommends rechecking every 1–2 years and making lifestyle changes to reduce your risk.

ADA A1C targets for people with diabetes

The ADA recommends an A1C of less than 7.0% for most non-pregnant adults with diabetes. A1C should be checked 2 to 4 times per year — quarterly if your diabetes is not well controlled or if you've recently changed treatment, and twice yearly if your blood sugar is stable and within target. However, targets should be individualised:

  • Lower goal (<6.5%): may suit people with shorter diabetes duration, younger age, no cardiovascular disease, or those managed with lifestyle/metformin only.
  • Higher goal (<8.0%): may be appropriate for people with a history of severe hypoglycaemia, limited life expectancy, advanced complications, or other illness.

Blood Sugar Ranges by Condition

Select a condition for specific ADA 2026 targets:

MeasurementADA 2026 Targetmmol/LNotes
Fasting / pre-meal80–130 mg/dL4.4–7.2Individualise for age and comorbidities
2 hrs post-meal<180 mg/dL<10.0Peak typically 1–2 hrs after eating
A1C<7.0%Lower (<6.5%) appropriate in some cases
Bedtime80–180 mg/dL4.4–10.0Discuss with your care team
Time in Range (TIR)>70%70–180 mg/dL per CGM; ADA/ATTD consensus
MeasurementADA 2026 Targetmmol/LNotes
Fasting / pre-meal80–130 mg/dL4.4–7.2CGM strongly recommended
2 hrs post-meal<180 mg/dL<10.0Post-meal monitoring critical with insulin
A1C<7.0%Without significant hypoglycaemia
Time in Range (TIR)>70%70–180 mg/dL
Time Below Range<4%<70 mg/dL; hypo prevention is priority
MeasurementDiagnostic Rangemmol/LNotes
Fasting glucose100–125 mg/dL5.6–6.9Impaired fasting glucose (IFG)
2-hr OGTT140–199 mg/dL7.8–11.0Impaired glucose tolerance (IGT)
A1C5.7–6.4%Recheck every 1–2 years
Goal with interventionReturn to normalLifestyle changes can reverse prediabetes
MeasurementADA 2026 Target (Pregnancy)mmol/LNotes
Fasting<95 mg/dL<5.3Tighter targets required in pregnancy
1 hr post-meal<140 mg/dL<7.8
2 hrs post-meal<120 mg/dL<6.7
A1C6.0–6.5%CGM preferred; avoid hypoglycaemia
MeasurementNormal Range (No Diabetes)mmol/LNotes
Fasting70–99 mg/dL3.9–5.5Optimal may be 70–90 for lowest CVD risk
2 hrs post-meal<140 mg/dL<7.8Healthy adults rarely exceed 140
A1C<5.7%Screen every 3 yrs from age 35
Peak glucose<160 mg/dL<8.9Spikes above 160 may warrant evaluation

Blood Sugar Levels by Age

The ADA diagnostic thresholds for diabetes are the same for all adults regardless of age. However, treatment targets are often adjusted based on age and individual health circumstances. Here is how blood sugar targets typically vary across life stages:

Age Group Normal Fasting Normal Post-Meal A1C Target (if diabetic)
Children (6–12) 70–120 mg/dL <140 mg/dL <7.0%
Adolescents (13–17) 70–120 mg/dL <140 mg/dL <7.0%
Adults (18–59) 70–99 mg/dL <140 mg/dL <7.0%
Adults (60–74) 70–99 mg/dL <140 mg/dL <7.5% (may be appropriate)
Older Adults (75+) 70–105 mg/dL <150 mg/dL <8.0–8.5% (complex/high-risk)
Pregnancy <95 mg/dL <120 mg/dL (2-hr) 6.0–6.5%
Diagnostic thresholds (fasting ≥126 mg/dL, A1C ≥6.5%) are the same for all adults. Age-based adjustments apply to treatment targets only, not diagnosis. Always discuss individual goals with your healthcare provider.
Why do targets differ for older adults?

Adults over 65 with multiple chronic conditions, cognitive impairment, limited life expectancy, or a high risk of falls may benefit from less aggressive glucose targets. Hypoglycaemia is more dangerous in this group — the risk of falls, cardiac events, and cognitive effects is higher. The ADA recommends a higher A1C ceiling (up to 8.5%) for older adults who are frail or have complex medical needs.

Dangerous Blood Sugar Levels

⚠ Emergency thresholds — seek immediate care

Severe hypoglycaemia: Blood sugar below 54 mg/dL (3.0 mmol/L) — seizure or loss of consciousness possible. Call 911 immediately.

Diabetic ketoacidosis (DKA): Blood sugar above 240 mg/dL (13.3 mmol/L) with ketones present. Seek urgent medical care.

Hyperosmolar hyperglycaemic state (HHS): Blood sugar above 600 mg/dL (33.3 mmol/L) — a life-threatening emergency. Call 911.

Levelmg/dLmmol/LRecommended Action
Severe hypoglycaemia<54<3.0Emergency — call 911
Hypoglycaemia<70<3.9Treat with 15g fast-acting carbs (15-15 rule)
Low-normal70–793.9–4.4Monitor; may need snack before exercise
Target range80–1304.4–7.2ADA fasting target for most adults with diabetes
Mildly elevated181–24010.1–13.3Monitor; consider medication adjustment
High — check ketones241–30013.4–16.7Check ketones; contact your care team
Very high301–60016.7–33.3Seek urgent medical attention
Critical — HHS risk>600>33.3Life-threatening — call 911
The 15-15 Rule for Hypoglycaemia

If blood sugar is below 70 mg/dL: eat or drink 15 grams of fast-acting carbohydrates (4 glucose tablets, 4 oz orange juice, 4 oz regular soda, or 1 tablespoon honey). Wait 15 minutes, then recheck. If still below 70, repeat. Once above 70, eat a small snack if your next meal is more than an hour away. If the person is unconscious or cannot swallow safely, call 911 — do not try to give food or drink.

What Affects Blood Sugar Levels?

Many factors beyond food and medication influence your blood glucose. Understanding them helps you interpret readings and avoid surprises. Factors can push blood sugar up, down, or in either direction depending on the situation.

🍞
Food (carbohydrates)
Carbohydrates raise blood sugar most directly. High-glycaemic foods (white bread, sugary drinks, white rice) cause faster, larger spikes than low-GI options (legumes, most vegetables, whole grains).
🏃
Physical activity
Exercise typically lowers blood sugar by helping muscles absorb glucose without insulin. However, intense anaerobic activity (sprinting, heavy lifting) can temporarily raise blood sugar due to stress hormones.
😰
Stress
Both physical stress (illness, injury, surgery) and emotional stress raise blood sugar by triggering cortisol and adrenaline release — both of which cause the liver to release stored glucose.
🌙
Sleep
Poor or insufficient sleep raises cortisol levels and reduces insulin sensitivity. Even one night of poor sleep can produce measurably higher fasting glucose the next morning.
💊
Medication
Insulin and most diabetes medications lower blood sugar. Steroids (prednisone), some antipsychotics, certain blood pressure drugs, and decongestants can raise it. Always review new medications with your care team.
🤒
Illness
When you're ill, your body releases stress hormones that raise blood sugar — even if you're eating less than usual. Monitor more frequently when sick and follow your sick-day management plan.
🍺
Alcohol
Alcohol can cause hypoglycaemia — especially if you drink without eating — because it blocks the liver from releasing stored glucose. It can also cause delayed hypoglycaemia hours later. Beer and sweet cocktails also contain carbohydrates that temporarily raise blood sugar.
🌡️
Heat & dehydration
Hot weather and dehydration can concentrate glucose in the blood, raising readings. Heat also dilates blood vessels and can affect how quickly insulin is absorbed from injection sites.

Symptoms of High and Low Blood Sugar

Symptoms alone should never be used to diagnose or confirm a blood sugar level — always use a glucose meter or CGM. Some people, particularly those with long-standing diabetes, experience few or no symptoms of hypoglycaemia (hypoglycaemia unawareness), which makes regular monitoring especially important.

Low Blood Sugar (<70 mg/dL)
  • Shakiness or trembling
  • Sweating, chills, clamminess
  • Rapid or irregular heartbeat
  • Dizziness or lightheadedness
  • Hunger, nausea
  • Blurred or double vision
  • Headache, irritability, anxiety
  • Pale skin colour
  • Confusion or difficulty concentrating
  • Loss of consciousness (severe)
High Blood Sugar (>180 mg/dL)
  • Frequent urination
  • Increased thirst
  • Blurred vision
  • Headache
  • Fatigue, weakness
  • Dry mouth
  • Slow-healing cuts or wounds
  • Fruity-smelling breath (DKA warning)
  • Nausea or vomiting (DKA)
  • Confusion (severe/HHS)

mg/dL to mmol/L Conversion

The US uses mg/dL as the standard unit for blood glucose. Most other countries use mmol/L. To convert: divide mg/dL by 18.016 to get mmol/L.

mg/dL
mmol/L
mg/dL
mmol/L
54
3.0
154
8.6
70
3.9
180
10.0
80
4.4
200
11.1
99
5.5
240
13.3
100
5.6
300
16.7
125
6.9
400
22.2
126
7.0
500
27.8
130
7.2
600
33.3

Blood Sugar Chart: Summary

The fasting blood sugar, 2-hour post-meal blood sugar, and A1C tests are the primary tools for diagnosing prediabetes and diabetes, and for monitoring how well diabetes is managed. If you think you have diabetes, do not attempt self-diagnosis with a home meter alone — formal laboratory testing is required.

If you have not been diagnosed but your results are above normal, your doctor may recommend additional tests and lifestyle changes, including weight management, a healthy eating plan, and regular physical activity. If you are diagnosed with diabetes, learning to monitor blood sugar with a meter or CGM is one of the most important steps you can take.

Read more: Blood Sugar Monitoring: When to Check and Why →

Frequently Asked Questions

A normal fasting blood sugar for someone without diabetes is 70–99 mg/dL (3.9–5.5 mmol/L). A level of 100–125 mg/dL indicates prediabetes. A level of 126 mg/dL or above on two separate tests is diagnostic of diabetes. For people already diagnosed with diabetes, the ADA recommends a fasting target of 80–130 mg/dL.

For people without diabetes, blood sugar at 2 hours after a meal should be below 140 mg/dL (7.8 mmol/L). For people with diabetes, the ADA recommends less than 180 mg/dL (10.0 mmol/L). A value of 140–199 mg/dL at 2 hours suggests prediabetes; 200 mg/dL or above may indicate diabetes.

A normal A1C for someone without diabetes is below 5.7%. An A1C of 5.7–6.4% indicates prediabetes. An A1C of 6.5% or above on two separate tests is diagnostic of diabetes. The ADA recommends less than 7.0% for most non-pregnant adults with diabetes, though individual targets vary.

Blood sugar above 240 mg/dL (13.3 mmol/L) warrants checking for ketones, as this level carries a risk of DKA in people on insulin or with type 1 diabetes. Blood sugar above 300 mg/dL requires urgent medical attention. Blood sugar above 600 mg/dL can cause hyperosmolar hyperglycaemic state (HHS) — a life-threatening emergency. Call 911.

Blood sugar below 70 mg/dL (3.9 mmol/L) is hypoglycaemia and should be treated immediately using the 15-15 rule (15g fast-acting carbs, recheck in 15 minutes). Blood sugar below 54 mg/dL (3.0 mmol/L) is clinically significant and requires urgent treatment. If the person cannot swallow safely or loses consciousness, call 911.

The ADA diagnostic thresholds are the same for all adults: fasting below 100 mg/dL is normal. However, treatment targets are often adjusted for older adults — an A1C of less than 8% (or even 8.5%) may be appropriate for adults over 65 with complex health needs or high hypoglycaemia risk. Children and teenagers with diabetes generally have the same targets as adults, managed by a paediatric diabetes team.

The ADA provides an estimated average glucose (eAG) formula to convert A1C into everyday mg/dL. Approximate conversions: A1C 5.0% ≈ 97 mg/dL · A1C 6.0% ≈ 126 mg/dL · A1C 7.0% ≈ 154 mg/dL · A1C 8.0% ≈ 183 mg/dL · A1C 9.0% ≈ 212 mg/dL · A1C 10.0% ≈ 240 mg/dL. The A1C is a weighted average — more recent weeks contribute more than earlier ones.

This is most likely the dawn phenomenon — a natural surge of hormones (including cortisol and growth hormone) that occurs in the early morning hours, typically between 4 and 8 AM. These hormones signal the liver to release stored glucose in preparation for waking activity. In people without diabetes, the body produces extra insulin to compensate. In people with diabetes, this compensation is impaired, causing fasting blood sugar to be higher than expected. The dawn phenomenon is distinct from the Somogyi effect (rebound hyperglycaemia after overnight low blood sugar) and is very common in both type 1 and type 2 diabetes. Adjusting medication timing, changing the timing of evening meals, or using a CGM to observe overnight trends can help — discuss with your care team.

A random blood glucose test is taken at any time of day, regardless of when you last ate. A result below 140 mg/dL (7.8 mmol/L) is generally considered normal. A result of 200 mg/dL (11.1 mmol/L) or above, when accompanied by classic symptoms of diabetes (thirst, frequent urination, unexplained weight loss), is diagnostic of diabetes. Random testing is useful in emergency or clinical settings, but fasting blood glucose or A1C tests are preferred for routine diabetes screening because they are less affected by recent food intake.

Time in range (TIR) is a measure used with continuous glucose monitors (CGMs) that shows what percentage of the day your blood sugar stays within a target range — typically 70–180 mg/dL for most adults with diabetes. The ADA and international consensus recommend a TIR of more than 70% as a key goal. TIR provides a more complete picture than A1C alone because it captures variability and time spent low as well as time spent high. See our guide to CGM for diabetes management →

Amy Campbell MS RD LDN CDCES
Amy Campbell, MS, RD, LDN, CDCES
Registered Dietitian · Certified Diabetes Care and Education Specialist

Amy Campbell is a Registered Dietitian and Certified Diabetes Educator at Good Measures, LLC. She is the author of Staying Healthy with Diabetes: Nutrition & Meal Planning and co-author of 16 Myths of a Diabetic Diet. She has written extensively for Diabetes Self-Management, Diabetes Spectrum, and Clinical Diabetes. Meet all our expert authors →

Sources & References

  • American Diabetes Association. Standards of Medical Care in Diabetes — 2026. Diabetes Care. 2026;49(Suppl 1).
  • American Diabetes Association. Diagnosis & A1C. diabetes.org.
  • American Diabetes Association. Checking Your Blood Sugar. diabetes.org.
  • Nathan DM, et al. Translating the A1C assay into estimated average glucose values. Diabetes Care. 2008;31(8):1473–1478.
  • Battelino T, et al. Clinical targets for continuous glucose monitoring data interpretation: recommendations from the international consensus on time in range. Diabetes Care. 2019;42(8):1593–1603.
  • American Diabetes Association. Hypoglycaemia (Low Blood Sugar). diabetes.org.

Medical disclaimer: The content on this page is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your physician or qualified healthcare provider regarding your blood sugar targets or diabetes management. Individual targets may differ from the general ADA guidelines shown here.