What Should My Blood Sugar Be?
Reviewed by the JForH team ·
If you have diabetes, the American Diabetes Association suggests 80–130 mg/dL before meals and under 180 mg/dL one to two hours after a meal starts, with an A1C below 7% for many adults. Without diabetes, a normal fasting blood sugar is under 100 mg/dL. Anything below 70 mg/dL is low and needs treating right away.
What should my blood sugar be if I have diabetes?
For many adults with diabetes, the goal is 80–130 mg/dL before meals and under 180 mg/dL after. Those are the American Diabetes Association (ADA) goals for adults who are not pregnant.
Your own goals may be different, so check them with your care team. This table shows the common targets from the ADA Standards of Care and the International Consensus on Time in Range.
| When or what | Common goal for many adults with diabetes |
|---|---|
| Fasting or before meals | 80–130 mg/dL (4.4–7.2 mmol/L) |
| 1–2 hours after the start of a meal | Under 180 mg/dL (10.0 mmol/L) |
| A1C (about a 3-month average) | Under 7% |
| CGM time in range (70–180 mg/dL) | More than 70% of the day (about 17 hours) |
| CGM time below 70 mg/dL | Less than 4% of the day (about 1 hour) |
| CGM time below 54 mg/dL | Less than 1% of the day (about 15 minutes) |
| CGM time above 180 mg/dL | Less than 25% of the day |
The CGM rows only matter if you wear a continuous glucose monitor. If you use a finger-stick meter, the first two rows are the ones to watch.
What is a normal blood sugar level without diabetes?
A normal fasting blood sugar is under 100 mg/dL. Doctors use lab tests with set cutoffs to tell normal from prediabetes and diabetes. These are the ADA and CDC ranges for adults:
| Test | Normal | Prediabetes | Diabetes |
|---|---|---|---|
| Fasting blood sugar (no food for at least 8 hours) | Under 100 mg/dL | 100–125 mg/dL | 126 mg/dL or higher |
| 2 hours into an oral glucose tolerance test | Under 140 mg/dL | 140–199 mg/dL | 200 mg/dL or higher |
| A1C | Under 5.7% | 5.7%–6.4% | 6.5% or higher |
These are lab numbers for diagnosis, not targets for daily checks. One high reading on a home meter doesn't mean you have diabetes. The ADA says a diagnosis usually needs two abnormal results, unless there are clear symptoms of very high blood sugar.
A random blood sugar of 200 mg/dL or higher with classic symptoms, such as strong thirst and passing a lot of urine, also points to diabetes.
What should my blood sugar be when I wake up?
Under 100 mg/dL if you don't have diabetes. If you do, the ADA suggests 80–130 mg/dL before breakfast for many adults.
Your waking number is your fasting number. Fasting means no food or drinks with calories for at least 8 hours, so the first check of the morning, before breakfast, is the one to use.
Here's an example. A morning reading of 118 mg/dL is inside the goal for someone with diabetes. In a person without diabetes, a fasting 118 on a lab test would be in the prediabetes range of 100–125 mg/dL.
What should my blood sugar be 2 hours after eating?
Under 180 mg/dL for many adults with diabetes, the ADA says. Check 1 to 2 hours after your first bite, not after you finish eating.
After-meal checks help most when your before-meal numbers are on target but your A1C is still above goal. Spikes after eating may be the reason.
For people without diabetes, the lab glucose tolerance test counts a 2-hour value under 140 mg/dL as normal.
Is 140 blood sugar after a meal bad?
Not if you have diabetes. A reading of 140 mg/dL after a meal is inside the ADA's under-180 goal.
The time of day changes the answer. As a fasting number, 140 is above the 80–130 mg/dL goal. And in someone without diabetes, a fasting lab value of 126 mg/dL or higher is in the diabetes range.
What if you don't have diabetes? On a lab glucose tolerance test, 140 mg/dL at 2 hours is where the prediabetes range (140–199 mg/dL) begins. A meter check after an ordinary meal is not the same test. If you're worried, ask your doctor for a lab test.
What A1C should I aim for?
Below 7% for many adults with diabetes. That equals an estimated average blood sugar of about 154 mg/dL.
The goal is set with you. Some people can safely aim lower. Others need a higher goal to stay safe from lows. Our A1C calculator shows what your own A1C means as an average.
What is a good time in range on a CGM?
More than 70% of the day between 70 and 180 mg/dL, which is about 17 hours out of 24.
A continuous glucose monitor (CGM) is a small sensor that checks your sugar every few minutes, day and night. Time in range is the share of readings between 70 and 180 mg/dL.
The International Consensus on Time in Range (Battelino and colleagues, Diabetes Care, 2019), which the ADA follows, set these goals for most adults with type 1 or type 2 diabetes:
- More than 70% in range
- Less than 4% below 70 mg/dL
- Less than 1% below 54 mg/dL
- Less than 25% above 180 mg/dL
The ADA suggests looking at about 14 days of CGM data at a time.
What should blood sugar be for seniors?
It depends on overall health, not age. The ADA section on older adults sets looser goals for people with more health problems. That helps prevent low blood sugar, which can lead to falls, confusion and hospital stays.
| Overall health | A1C | Before meals | At bedtime | CGM |
|---|---|---|---|---|
| Healthy: few other long-term illnesses, memory and daily activities intact | Under 7.0–7.5% | 80–130 mg/dL | 80–180 mg/dL | 70% or more in range; 4% or less below 70 |
| Complex or intermediate: several long-term illnesses, trouble with everyday tasks, or mild to moderate memory problems | Under 8.0% | 90–150 mg/dL | 100–180 mg/dL | 50% or more in range; under 1% below 70 |
| Very complex or poor health: long-term care, end-stage illness, or moderate to severe memory problems | Do not rely on A1C | 100–180 mg/dL | 110–200 mg/dL | No set goal |
Take someone in the middle row, living with several long-term illnesses. Their goals might be 90–150 mg/dL before meals, 100–180 mg/dL at bedtime and an A1C under 8.0%.
What blood sugar is too low?
Under 70 mg/dL is too low, and you should treat it right away. The ADA groups low blood sugar (hypoglycemia) into three levels:
| Level | Blood sugar | What it means |
|---|---|---|
| Level 1 | Under 70 mg/dL (3.9 mmol/L) and 54 mg/dL or higher | Low. Treat it now. |
| Level 2 | Under 54 mg/dL (3.0 mmol/L) | Very low. Needs quick treatment. |
| Level 3 | Any number | Severe: you are confused or cannot treat yourself and need help from someone else. |
Signs of a low tend to come on quickly. You may feel shaky, hungry, tired, dizzy or irritable. Some people get a headache, a fast or uneven heartbeat, confusion, or trouble seeing or speaking clearly.
After repeated lows, some people stop feeling these warning signs. Being 65 or older also raises the risk of lows, according to the NIDDK.
What do I do if my blood sugar is low?
Use the 15-15 rule. The CDC and ADA recommend it for a low under 70 mg/dL when you are awake and able to swallow:
- Have 15 grams of fast-acting sugar. The ADA says glucose tablets or gel are preferred. The CDC also lists half a cup (4 ounces) of juice or regular, non-diet soda, or 1 tablespoon of sugar or honey.
- Wait 15 minutes, then check your blood sugar again.
- If it's still under 70 mg/dL, repeat.
- Once you're back in range, eat a snack or meal with protein and carbohydrates so it doesn't drop again.
If someone has passed out, is having a seizure or can't swallow safely, don't put food or drink in their mouth. Glucagon, given as a shot or nasal spray, is the best treatment for a severe low. Family members can be taught to give it.
Call 911 right after giving glucagon, or right away if there is none. The ADA recommends a glucagon prescription for everyone who takes insulin or is at high risk of lows.
When should I call my doctor about my blood sugar?
- You've had a low under 70 mg/dL more than once, any low under 54 mg/dL, or a low you didn't feel coming.
- Your readings are often above the goals you agreed with your care team, or your A1C is above goal.
- You're sick, not eating normally or have started a new medicine, and your numbers have changed.
- A home or pharmacy test shows a high reading and you've never been told you have diabetes. Ask for a lab test to check.
Get emergency help for a severe low. Do the same for high blood sugar with vomiting, trouble breathing, confusion or extreme drowsiness.
This guide is for education and does not replace advice from your own doctor.
Convert your A1C to average blood sugar
Common questions
What is a normal blood sugar level?
For adults without diabetes, a normal fasting blood sugar is under 100 mg/dL, and a 2-hour value on a glucose tolerance test is under 140 mg/dL. A fasting 100–125 mg/dL is prediabetes, and 126 mg/dL or higher is in the diabetes range.
What should blood sugar be 2 hours after eating?
Under 180 mg/dL for many adults with diabetes, measured 1 to 2 hours after the start of the meal, the ADA suggests. Without diabetes, a 2-hour glucose tolerance test result under 140 mg/dL is normal.
What should my blood sugar be when I wake up?
With diabetes, the ADA suggests 80–130 mg/dL before breakfast for many adults. Without diabetes, a normal fasting level is under 100 mg/dL.
Is 140 a good blood sugar level?
It depends on when you checked. After a meal, 140 mg/dL is within the ADA's under-180 goal for people with diabetes. As a fasting number it is above the 80–130 mg/dL goal, and in someone without diabetes a fasting 126 mg/dL or higher is in the diabetes range.
What blood sugar level is too low?
Under 70 mg/dL is low and should be treated with the 15-15 rule. Under 54 mg/dL is very low. Any low where you need someone else's help is severe.
What is the 15-15 rule?
For a low under 70 mg/dL, have 15 grams of fast-acting sugar, such as glucose tablets or 4 ounces of juice. Wait 15 minutes and check again. Repeat until you're above 70 mg/dL, then eat a snack or meal.
What should blood sugar be for seniors?
The ADA sets goals by health, not age. Healthy older adults often aim for 80–130 mg/dL before meals and an A1C under 7.0–7.5%. Those with several illnesses or memory problems may aim for 90–150 mg/dL and an A1C under 8.0%.
What is a good time in range on a CGM?
For most adults with diabetes, the goal is more than 70% of readings between 70 and 180 mg/dL and less than 4% below 70 mg/dL. Older adults with complex health may aim for 50% or more in range and under 1% below 70 mg/dL.
Can a home meter tell me if I have diabetes?
No. Home meters and CGMs are not used to diagnose diabetes. If you get a high reading, ask your doctor for a lab test such as fasting plasma glucose or A1C.
Sources
- American Diabetes Association. 6. Glycemic Goals, Hypoglycemia, and Hyperglycemic Crises: Standards of Care in Diabetes—2026. Diabetes Care. 2026;49(Suppl 1):S132-S149
- American Diabetes Association. 2. Diagnosis and Classification of Diabetes: Standards of Care in Diabetes—2026. Diabetes Care. 2026;49(Suppl 1):S27-S49
- American Diabetes Association. 13. Older Adults: Standards of Care in Diabetes—2026. Diabetes Care. 2026;49(Suppl 1)
- 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
- CDC. Diabetes Testing
- CDC. Treatment of Low Blood Sugar (Hypoglycemia)
- NIDDK. Low Blood Glucose (Hypoglycemia)
- Nathan DM et al. Translating the A1C assay into estimated average glucose values (ADAG study). Diabetes Care. 2008;31(8):1473-1478
Last updated: . Educational information, not medical advice. Talk to your doctor before changing your treatment.