For most adults with diabetes, blood sugar should be 80 to 130 mg/dL before a meal and under 180 mg/dL two hours after eating. These are the standard targets, but your ideal range depends on your age, how long you’ve had diabetes, whether you’re pregnant, and what medications you take.
Standard Blood Sugar Targets for Adults
The two numbers most people with diabetes track are fasting (or pre-meal) blood sugar and post-meal blood sugar. The CDC puts the targets for non-pregnant adults at:
- Before a meal: 80 to 130 mg/dL
- Two hours after eating: Less than 180 mg/dL
These ranges apply to both Type 1 and Type 2 diabetes. They’re meant to keep blood sugar high enough to fuel your brain and muscles while staying low enough to avoid the damage that prolonged high glucose causes to blood vessels, nerves, and organs over time.
What A1C Means and Where It Should Be
A single blood sugar reading is a snapshot. Your A1C is more like a three-month average. It measures the percentage of your red blood cells that have glucose attached to them, giving a picture of how well your blood sugar has been controlled over roughly 90 days.
For most adults with diabetes, the goal is an A1C of 7% or less. That roughly translates to an average blood sugar of about 154 mg/dL. A lower A1C generally means a lower risk of diabetes-related complications like nerve damage, kidney disease, and vision loss. Some people aim for 6.5% or below, particularly if they can reach it without frequent episodes of low blood sugar.
Targets During Pregnancy
Blood sugar targets tighten significantly during pregnancy because even moderately 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
These apply whether you had diabetes before pregnancy or developed gestational diabetes during it. The tighter range helps reduce the risk of the baby growing too large, premature delivery, and blood sugar problems in the newborn after birth.
Targets for Children and Teens
Children with Type 1 diabetes follow similar daily ranges but with slightly wider boundaries to account for unpredictable eating and activity patterns. International pediatric guidelines recommend pre-meal blood sugar of 70 to 144 mg/dL and post-meal readings of 70 to 180 mg/dL for kids using a fingerstick meter.
The A1C goal for most children is 7% or less. Kids who use a continuous glucose monitor paired with an automated insulin pump can sometimes aim for 6.5% or less, as long as doing so doesn’t cause frequent lows or add stress that affects quality of life. The broader goal for children on continuous monitors is spending more than 70% of the day between 70 and 180 mg/dL.
Adjusted Targets for Older Adults
Targets loosen as people age, particularly for those managing several health conditions or experiencing frailty. The reason is practical: in older adults, the immediate danger of blood sugar dropping too low (causing falls, confusion, or heart problems) often outweighs the long-term risk of complications from slightly higher glucose.
For older adults who are still functionally independent, the A1C target stays at 7% or below. For those who are functionally dependent or living with frailty or dementia, a target of up to 8% or even 8.5% is considered appropriate. Pre-meal blood sugar targets shift upward too, from the standard 80 to 130 range to as high as 108 to 162 mg/dL for frail individuals. The priority shifts to avoiding dangerous lows and keeping blood sugar comfortable rather than optimizing for long-term prevention.
When Blood Sugar Is Too Low
A reading of 70 mg/dL or below is considered low blood sugar, or hypoglycemia. At this level, you may feel shaky, sweaty, dizzy, or suddenly hungry. Some people get irritable or confused. Severe lows, typically below 54 mg/dL, can cause seizures or loss of consciousness and require someone else to help you.
Low blood sugar is most common in people taking insulin or certain oral medications that stimulate insulin production. It can be triggered by skipping meals, exercising more than usual, or taking too much medication. Treating a mild low is straightforward: consume 15 grams of fast-acting carbohydrate (four glucose tablets, half a cup of juice, or a tablespoon of honey), wait 15 minutes, and recheck.
When Blood Sugar Is Dangerously High
Blood sugar that stays at 250 mg/dL or above warrants close attention. At this level, you should check every four to six hours and test your urine for ketones, which are acids your body produces when it starts burning fat instead of glucose for fuel. A buildup of ketones can lead to diabetic ketoacidosis, a life-threatening condition most common in Type 1 diabetes but possible in Type 2 as well.
If your blood sugar stays at 300 mg/dL or above, that’s an emergency. Symptoms of ketoacidosis include nausea, vomiting, abdominal pain, fruity-smelling breath, and rapid breathing. This requires emergency medical care.
How Often to Check Your Blood Sugar
How frequently you test depends almost entirely on your treatment plan. If you have Type 1 diabetes, you may need to check 4 to 10 times per day: before meals and snacks, before and after exercise, at bedtime, and sometimes during the night. Many people with Type 1 use a continuous glucose monitor that reads levels automatically every few minutes, which reduces the need for fingersticks.
If you have Type 2 diabetes and take insulin, you’ll likely test several times a day. People on multiple daily injections often check before meals and at bedtime. Those on a single long-acting insulin dose may only need to test before breakfast and occasionally before dinner.
If you manage Type 2 diabetes with non-insulin medications, diet, and exercise alone, daily testing may not be necessary. Your doctor will typically rely more on periodic A1C tests to gauge your overall control. That said, checking more frequently makes sense when you’re sick, traveling, changing your exercise routine, or starting a new medication.
Why Your Target Might Differ
The ranges above are starting points. Your specific targets could be tighter or looser depending on several factors: how long you’ve had diabetes, your risk of low blood sugar episodes, whether you have heart disease or kidney disease, your age, and how aware you are when your blood sugar drops (some people lose the ability to feel early warning signs of lows, a condition called hypoglycemia unawareness). Someone who is young, newly diagnosed, and otherwise healthy will typically aim for tighter control than someone who is elderly with multiple chronic conditions and a history of severe lows.