A good fasting blood sugar reading is below 100 mg/dL (5.6 mmol/L). Two hours after eating, a healthy reading falls below 140 mg/dL (7.8 mmol/L). These are the benchmarks for someone without diabetes, but “good” shifts depending on whether you’re managing diabetes, pregnant, or checking your child’s levels.
Fasting Blood Sugar Targets
Fasting blood sugar is measured after at least eight hours without food, typically first thing in the morning. Below 100 mg/dL is considered normal. A reading between 100 and 125 mg/dL falls into the prediabetes range, sometimes called impaired fasting glucose. At 126 mg/dL or above on two separate tests, the result points to diabetes.
That 100 mg/dL threshold is worth paying attention to. Many people assume they’re fine as long as they haven’t been diagnosed with diabetes, but fasting levels in the low 100s already signal that the body is struggling to regulate glucose overnight. Catching this early gives you a real window to change course through diet and exercise before the numbers climb further.
After-Meal Blood Sugar Levels
Your blood sugar naturally rises after eating, then insulin brings it back down. In a healthy body, levels should return to normal within about two hours. A reading below 140 mg/dL at the two-hour mark is considered normal on a glucose tolerance test. Anything from 140 to 199 mg/dL suggests prediabetes, and 200 mg/dL or higher indicates diabetes.
The two-hour window is the standard measurement point, but blood sugar typically peaks somewhere between 45 minutes and 90 minutes after your first bite. If you’re using a home meter and want to catch your highest spike, testing at the one-hour mark can be informative, though most clinical guidelines use the two-hour reading for formal assessment.
What Your A1c Number Means
While a finger-stick or fasting test captures a single moment, A1c reflects your average blood sugar over roughly three months. It measures the percentage of your red blood cells that have glucose attached to them. The higher your blood sugar has been running, the higher the percentage.
A normal A1c is below 5.7%. Between 5.7% and 6.4% is prediabetes. At 6.5% or above, the result indicates diabetes. Because A1c represents an average, it won’t reveal daily highs and lows, but it’s one of the most reliable ways to see the bigger picture.
Here’s how A1c percentages translate to estimated average glucose:
- 5% = roughly 97 mg/dL
- 6% = roughly 126 mg/dL
- 7% = roughly 154 mg/dL
- 8% = roughly 183 mg/dL
- 9% = roughly 212 mg/dL
For most people with diabetes, the general A1c goal is below 7%, which corresponds to an average glucose of about 154 mg/dL. Your specific target may differ based on age, how long you’ve had diabetes, and other health conditions.
Targets if You Have Diabetes
If you’re living with type 1 or type 2 diabetes, “good” doesn’t mean the same thing as it does for someone without the condition. The realistic target range widens. Most guidelines recommend keeping blood sugar between 70 and 180 mg/dL for the majority of the day.
If you use a continuous glucose monitor (CGM), the key metric is called Time in Range. This measures what percentage of your day you spend between 70 and 180 mg/dL. The goal for most adults is at least 70% of the day in that window, which works out to about 17 hours out of 24. Spending less than 4% of the day below 70 mg/dL (roughly one hour) is the typical target for avoiding dangerous lows.
Perfectionism with blood sugar control can backfire. Pushing too aggressively toward non-diabetic numbers increases the risk of hypoglycemia, where blood sugar drops low enough to cause shakiness, confusion, or worse. A consistent 70% Time in Range is a genuinely strong result that correlates with a lower risk of long-term complications.
Blood Sugar Targets During Pregnancy
Pregnancy tightens the targets considerably because elevated blood sugar affects fetal development. Whether you have gestational diabetes or entered pregnancy with an existing diagnosis, the recommended levels are lower than standard diabetes targets:
- Fasting: below 95 mg/dL
- One hour after eating: below 140 mg/dL
- Two hours after eating: below 120 mg/dL
Notice that the post-meal targets use both the one-hour and two-hour marks. During pregnancy, many providers ask you to check at one hour after meals rather than two, since catching and correcting early spikes matters more in this context. These tighter windows can feel demanding, but they apply for a limited time and make a measurable difference in outcomes for both mother and baby.
Targets for Children
For children with type 1 diabetes, the A1c goal is generally below 7%, the same as adults. But day-to-day blood sugar targets are slightly more flexible. Starting goals are typically 71 to 180 mg/dL during the daytime and 101 to 200 mg/dL at bedtime. The bedtime range runs higher intentionally, providing a safety buffer against overnight lows when a child is asleep and can’t recognize or report symptoms.
Younger children who can’t yet describe how they feel when their blood sugar drops may need even more conservative targets. The priority is preventing severe lows, which can be dangerous in kids who won’t tell you something feels wrong.
Why Readings Fluctuate
Blood sugar is not static. It shifts throughout the day in response to food, activity, stress, sleep quality, illness, and hormones. A single high reading after a large meal doesn’t mean something is wrong, just as a single perfect fasting number doesn’t guarantee overall good control.
Carbohydrate-heavy meals cause larger spikes than meals built around protein, fat, and fiber. Physical activity pulls glucose into muscles, often lowering blood sugar for hours afterward. Stress and poor sleep raise it by triggering hormones that release stored glucose. Even the time of day matters: many people run higher in the early morning due to a natural hormonal surge sometimes called the dawn phenomenon.
If you’re checking at home, testing at consistent times gives you the most useful picture. A fasting reading each morning plus occasional checks two hours after meals will reveal patterns that a single lab draw can miss. Trends over days and weeks tell you far more than any individual number on the screen.