A good blood sugar level for someone without diabetes is between 70 and 99 mg/dL when measured after fasting. After eating, a healthy reading stays below 140 mg/dL. These numbers shift depending on whether you’re managing diabetes, pregnant, or older, so the “good” range isn’t one-size-fits-all.
Normal Fasting Blood Sugar
Fasting blood sugar is measured after you haven’t eaten for at least eight hours, typically first thing in the morning. For a healthy adult without diabetes, the normal range is 70 to 99 mg/dL. Some people naturally run between 50 and 70 mg/dL without symptoms, and that can still be normal.
Once your fasting level reaches 100 to 125 mg/dL, it falls into the prediabetes range. At 126 mg/dL or higher on two separate tests, the result meets the threshold for a diabetes diagnosis.
Blood Sugar After Meals
Your blood sugar rises after you eat, peaking roughly one to two hours after your first bite. In a person without diabetes, that peak generally stays below 140 mg/dL and then drops back down as insulin does its job. A reading between 140 and 199 mg/dL two hours after a glucose-heavy drink signals prediabetes, while 200 mg/dL or above points to diabetes.
You don’t need to test after every meal unless your doctor has asked you to. But if you’re monitoring at home, checking one to two hours after eating gives you the most useful snapshot of how your body handles food.
A1C: Your Two-to-Three-Month Average
A1C measures the percentage of your red blood cells that have sugar attached to them. Because red blood cells live about three months, the test reflects your average blood sugar over that window rather than a single moment in time.
- Normal: below 5.7%
- Prediabetes: 5.7% to 6.4%
- Diabetes: 6.5% or higher
An A1C of 7% translates to an estimated average glucose of about 154 mg/dL. For most nonpregnant adults managing diabetes, staying below 7% is the standard goal. That target can be loosened or tightened depending on age, how long you’ve had diabetes, and your risk of low blood sugar episodes.
Targets for People Managing Diabetes
If you already have a diabetes diagnosis, “good” blood sugar looks different than it does for someone without the condition. The American Diabetes Association recommends these daily targets for most nonpregnant adults with diabetes:
- Before meals: 80 to 130 mg/dL
- One to two hours after a meal: below 180 mg/dL
- A1C: below 7%
These numbers balance good blood sugar control against the real risk of going too low. Older adults or people with other serious health conditions often aim for slightly higher targets, because a severe low blood sugar episode can be more dangerous for them than running a little high.
Blood Sugar Targets During Pregnancy
Pregnancy tightens the acceptable range considerably. For women with gestational diabetes, the recommended targets are:
- Fasting: 95 mg/dL or lower
- One hour after a meal: 140 mg/dL or lower
- Two hours after a meal: 120 mg/dL or lower
Women who had type 1 or type 2 diabetes before becoming pregnant have even tighter goals: fasting levels between 60 and 99 mg/dL, and post-meal peaks between 100 and 129 mg/dL. These stricter ranges protect both the mother and the developing baby.
When Blood Sugar Drops Too Low
Low blood sugar, or hypoglycemia, is typically defined as anything below 70 mg/dL. It’s classified in levels of severity:
- Mild (54 to 69 mg/dL): You may feel shaky, sweaty, or lightheaded. Eating a fast-acting carbohydrate like juice or glucose tablets usually resolves it.
- Moderate (below 54 mg/dL): Symptoms intensify. Confusion and difficulty concentrating are common. This level needs prompt treatment.
- Severe: You may need someone else’s help to recover, regardless of the number on the meter. Confusion, seizures, or loss of consciousness can occur.
If you don’t take diabetes medications, significant low blood sugar is uncommon. It’s mostly a concern for people using insulin or certain oral medications that push the pancreas to produce more insulin.
Why Morning Readings Run High
If your fasting number is higher than expected, your body’s overnight hormones may be the reason. Between roughly 3 and 8 a.m., your liver ramps up glucose production in response to cortisol and growth hormone. This natural process, called the dawn phenomenon, gives you energy to wake up. In someone without diabetes, insulin rises to match. If you have diabetes or insulin resistance, that counter-response falls short, and you wake up with an elevated reading.
A separate pattern, called the Somogyi effect, happens when blood sugar drops too low during the night. Your body overcorrects by releasing stored glucose, and you wake up high. The difference matters because the fixes are opposite: the dawn phenomenon may call for adjusting medication timing, while the Somogyi effect means addressing the overnight low that triggered the rebound.
Continuous Glucose Monitors and Time in Range
If you wear a continuous glucose monitor, your blood sugar is tracked in real time, giving you a much fuller picture than occasional finger sticks. The key metric is “time in range,” which measures what percentage of the day your glucose stays between 70 and 180 mg/dL.
For most adults with diabetes, the goal is spending more than 70% of the day in that 70 to 180 mg/dL window, which works out to roughly 17 hours. Equally important is minimizing time spent low: less than 4% of the day below 70 mg/dL (under one hour) and less than 1% below 54 mg/dL (under 15 minutes). For older adults or those at higher risk from lows, the time-in-range target drops to 50% or more, with stricter limits on time spent below range.
During pregnancy with type 1 diabetes, the target range narrows to 63 to 140 mg/dL, with the same 70% time-in-range goal. This tighter window reflects the need for closer control during pregnancy.