What You Should Know About Time-in-Range

Measuring a person’s HbA1C (A1C) used to be the only way to assess blood sugar management. It became a routine part of quarterly diabetes checkups starting in the early 90s. But now it’s 2026, and time-in-range (TIR) is becoming an increasingly valuable way to evaluate someone’s blood sugar management. 

This is largely thanks to the evolution from blood glucose meters (BGMs) to the widespread use of continuous glucose monitors (CGMs). While a person’s A1C level is still a valuable metric for  healthcare providers (HCPs), TIR helps people with diabetes make smarter decisions about things like insulin dosing, nutrition and activity.

TIR can be very helpful for daily diabetes management. In this guide, we unpack what it is, how  HCPs use it, and how you can use it to your advantage in day-to-day life.

What is time-in-range?

TIR is a metric that shows what percentage of the day your blood glucose levels  are within your goal range. While using a CGM, you’ll work with your healthcare team to set low and high alarms that determine the appropriate goal range for your blood sugar levels. TIR tells you how often you’re actually within that goal range.

For example, your personal TIR might be an average of 65% within a goal range of 4.4 to 10.0 mmol/L (80 to 180 mg/dL). This means your blood glucose levels are within that range for about 65% of the day and outside that range for the remaining 35% of the day. The 2026 American Diabetes Association (ADA) Standards of Care in Diabetes  refers to  glucoses outside your goal TIR  as time below range (TBR) and time above range (TAR).

Today’s CGM technology can also offer more in-depth detail (graphs, charts, etc.) about your blood sugar levels with software like:

• Dexcom Clarity
• Abbott LibreView
• MiniMed (formerly Medtronic Diabetes) CareLink
• Tandem Source

Measuring TIR is possible with a CGM because most devices check your blood sugar at least every five minutes. A traditional finger-stick method could give similar data, but it’s not practical or realistic for most people, not to mention, it would be quite painful for your fingertips!

What’s the difference between A1C and time-in-range?

Discovered in 1968, your A1C result is still valuable, but it can overlook some critical aspects of your blood sugar levels, your safety and your overall wellbeing as a person with diabetes.

“I place immense value on time-in-range because it relates directly to a person’s quality of life,” says Gary Scheiner, CDCES, MS, author of “Think Like a Pancreas,” and founder of Integrated Diabetes Services.

While an A1C measurement gives you a general idea of your eAG (estimated average glucose level), it won’t tell you whether you’re experiencing several severe low blood sugars every day or bouncing between high and low regularly. It simply provides insight into the middle of that range. Frequent low blood sugars could also result in an artificially lower A1C.

A1C levels are also considered a flawed measurement compared to TIR because your A1C measures the glucose attached to the red blood cells in your body, but it’s only measuring a small percentage of those red blood cells. 

Additionally, the newer the red blood cell, the less glucose it carries, and the rate at which a person produces new red blood cells can vary widely from person to person and is affected by factors such as pregnancy or a recent blood donation. 

• In other words: it’s simply not a very accurate assessment of blood sugar health.

In TIR, two important variables are the general accuracy of your CGM and how often you’re wearing it. Otherwise, it can paint a very clear picture of your blood sugar levels day to day.

What should your goal range be for blood sugar levels?

Diabetes is highly individual, and your goal range is no different. 

Determining the right goal range for you can depend on a variety of factors, including:

• Age (young child vs. teenager vs. adult vs. older adults)
• Experience in managing diabetes
• Access to diabetes education
• Experience in managing insulin
• Ability to feel symptoms of low blood sugar (hypoglycemia awareness)
• Experience or trauma with severe hypoglycemia (low blood sugar)
• Access to diabetes medications and/or technology
• How you personally feel at different blood sugar levels
• Managing diabetes during pregnancy
• Managing diabetes amidst other health issues
• Lifestyle factors like being a parent, driving a lot, intense activity level, etc.

“It should be customized to the individual,” Scheiner says. “The universal range of 3.9 to 10.0 mmol/L (70 to 180 mg/dL) does not apply to everyone. The thing about time-in-range is that you have to first decide what that ‘feel-good’ range is for you.”

While someone on a very strict low-carb diet might be comfortable at 4.2 mmol/L (75 mg/dL) because they take very small doses of insulin and have limited complicating factors which may minimize their risk of hypoglycemia, that level might feel too risky for someone on a higher-carbohydrate diet, a parent of two small children or someone who drives their car all day for work.

“Some people are more comfortable on the slightly higher side,” Scheiner says. “And others find their happy zone when blood glucose levels are very tight.”

For someone who’s experienced a seizure during a severe low blood sugar episode, lingering below 5.5 mmol/L (100 mg/dL) could trigger significant anxiety, which means you may need a higher goal range as you address that trauma. Always check-in with your HCP about your nutrition goals and habits, target blood sugar ranges, mental health and other diabetes-related concerns. 

What is a “healthy” time-in-range goal?

The first and most important detail regarding your TIR percentage is really about the amount of time you are below range—remember, your TBR.

Low blood sugars are not only uncomfortable and tedious but also dangerous. 

As of 2025, ADCES recommends the following guidelines on CGM metrics and TIR:

Keep in mind that these guidelines are designed to help you stay as healthy as possible while also minimizing your risk of severe hypoglycemia.

It’s also important to know that when assessing your TIR, achieving a higher TIR percentage might mean you see a slight increase in your A1C if you’ve significantly reduced the number of low blood sugar episodes you experience. This is a good thing, and it’s another example of why the TIR tells you more than your A1C might.

“Clearly, we try to minimize time in a hypoglycemic zone, and less than 4% is ideal for most people,” Scheiner says. “But other than that, the optimal percentages depend on your personal high and low thresholds, and your personal goals and capabilities.”

Work with your healthcare team to understand your personal TIR and set meaningful goals. Remember, a “healthy” TIR varies for each person with diabetes—while general guidelines exist, every person is unique, and treatment plans should be adjusted for your specific needs.

Beyond the doctor’s office: explore the Time in Range Coalition

If you are new to TIR, you may also find support through resources like the Time in Range Coalition, which comprises a group of diabetes researchers, leaders, diabetes-focused organizations, like-minded partners and community members who provide insights that help people with diabetes (PWD) respond to blood sugar in real time.

You can get started with the Time in Range Coalition under a few different paths:

• If you’re just getting started
• If you know a bit already
• If you already use time in range every day
• If you’re navigating technology and pregnancy
• If you’d like to be inspired by other success stories

It’s more about improving TIR. When your TIR improves, so does your quality of life and complication risk. The coalition believes TIR is key, and it all starts there when it comes to helping PWD truly thrive.

At the end of the day, TIR isn’t just a data point your HCPs hammers into you during your regular checkups. It’s a starting point for PWD to get more out of life. We all deserve that!

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