A good blood sugar level for someone without diabetes is between 60 and 100 mg/dL before meals, and under 140 mg/dL after eating. These numbers shift depending on your age, whether you’re pregnant, and whether you’re managing diabetes or prediabetes. Here’s what the ranges mean and how to interpret yours.
Normal Blood Sugar Ranges
If you don’t have diabetes or prediabetes, your body keeps blood sugar in a fairly tight window throughout the day. Overnight and before meals, a healthy range is 60 to 100 mg/dL. After eating, blood sugar rises but typically stays below 140 mg/dL, then drops back down within a couple of hours as insulin does its job.
These numbers come from a fasting blood sugar test, which measures glucose after you haven’t eaten for at least eight hours. It’s the most common screening tool, and the cutoffs are straightforward:
- Normal: 99 mg/dL or below
- Prediabetes: 100 to 125 mg/dL
- Diabetes: 126 mg/dL or above
A glucose tolerance test, where you drink a sugary solution and get tested two hours later, uses different thresholds. Normal is 140 mg/dL or below, prediabetes falls between 140 and 199 mg/dL, and 200 mg/dL or above indicates diabetes. A random blood sugar reading of 200 mg/dL or higher at any point also meets the diagnostic threshold for diabetes.
What A1C Tells You
While a fasting test captures a single moment, the A1C test reflects your average blood sugar over the past two to three months. It measures the percentage of hemoglobin (a protein in red blood cells) that has glucose attached to it. The higher your blood sugar has been running, the higher that percentage climbs.
- Normal: below 5.7%
- Prediabetes: 5.7% to 6.4%
- Diabetes: 6.5% or above
A1C is useful because it isn’t thrown off by what you ate yesterday or whether you slept poorly. It gives a broader picture. If your fasting glucose looks fine but your A1C is creeping above 5.7%, your blood sugar may be spiking higher than normal after meals even though it returns to baseline by morning.
Targets During Pregnancy
Pregnancy calls for tighter blood sugar control because elevated glucose can affect fetal development. The American College of Obstetricians and Gynecologists recommends these targets for pregnant women with diabetes:
- Fasting: below 95 mg/dL
- One hour after eating: below 140 mg/dL
- Two hours after eating: below 120 mg/dL
- A1C: no higher than 6%
Notice the fasting target is lower than the general population cutoff, and the post-meal windows are measured more precisely. Most women managing gestational diabetes check their blood sugar several times a day to stay within these ranges.
Targets for Children
Children with diabetes use wider target ranges than adults, especially younger kids whose blood sugar can swing more unpredictably and who may not recognize or communicate symptoms of a low. General pediatric goals look like this:
- Under 5 years: 80 to 200 mg/dL
- Ages 5 to 11: 70 to 180 mg/dL
- Ages 12 and up: 70 to 150 mg/dL
The broader range for younger children reflects a safety-first approach. Low blood sugar in a toddler is more dangerous and harder to catch than a reading that runs a little high, so the upper limit is more generous.
How Age Affects Targets in Adults
Blood sugar goals aren’t one-size-fits-all for adults either. The American Diabetes Association notes that targets are individualized based on age, life expectancy, and overall health. For older adults or people with multiple chronic conditions, slightly higher targets may be appropriate because the risks of low blood sugar (falls, confusion, heart strain) can outweigh the long-term benefits of very tight control.
For most adults with type 1 or type 2 diabetes, the general A1C goal is under 7%. For older or high-risk individuals, a provider may set the goal closer to 7.5% or 8%. Younger, otherwise healthy adults may aim lower. The key principle is that tighter control reduces complications over decades, but aggressive targets increase the chance of dangerous lows.
Time in Range: A Newer Way to Measure
If you wear a continuous glucose monitor (CGM), you’ll see a metric called “Time in Range,” which tracks the percentage of the day your blood sugar stays between 70 and 180 mg/dL. International consensus guidelines recommend these targets for adults with type 1 or type 2 diabetes:
- Time in range (70 to 180 mg/dL): more than 70% of the day, or roughly 17 hours
- Time below 70 mg/dL: less than 4% of the day, or under 1 hour
- Time above 180 mg/dL: less than 25% of the day, or under 6 hours
- Time above 250 mg/dL: less than 5% of the day, or under about 1 hour
For older or high-risk adults, the time-in-range goal drops to above 50% (about 12 hours), with a stronger emphasis on avoiding severe lows. Every 5% improvement in time in range is associated with meaningful clinical benefits, so even small gains matter. Time in range is especially helpful because it shows patterns that a single fasting test or quarterly A1C can’t capture, like a post-lunch spike that resolves by dinner.
When Blood Sugar Drops Too Low
A good blood sugar level isn’t just about avoiding highs. Going too low is dangerous in its own way. Blood sugar below 70 mg/dL is considered low, and below 54 mg/dL is classified as severe.
Early symptoms include a fast heartbeat, shaking, sweating, anxiety, dizziness, and sudden hunger. These are your body’s alarm signals, driven by a burst of stress hormones trying to push glucose back up. If blood sugar keeps falling, symptoms escalate to weakness, blurred vision, confusion, and in extreme cases, seizures. People who take insulin or certain diabetes medications are most at risk, but it can also happen after prolonged exercise or skipping meals.
Why Morning Readings Can Run High
If you’ve ever checked your blood sugar first thing in the morning and found it higher than expected, you may be seeing the dawn phenomenon. In the early morning hours, your body releases a wave of hormones, including growth hormone, cortisol, and glucagon, that naturally increase insulin resistance. This is a normal biological process meant to give you energy to start the day, but it can push fasting glucose higher than it was at 2 a.m.
The dawn phenomenon is common in people with diabetes and can also show up in prediabetes. It’s one reason a single fasting reading doesn’t always tell the full story. If your morning numbers seem inconsistent with how well you’re eating and exercising, this hormonal pattern may be the explanation.