Keeping glucose levels in a healthy range is a key part of diabetes management. A newer metric, known as Time in Range, helps show how often people stay within the target range and how they may need to adjust their care plans.

Time in range is a newer measurement for diabetes glucose management, a percentage that reflects how much time your blood sugar levels are in the particular target range you’ve discussed with your healthcare team.

This diabetes management data point has emerged in recent years, complementing the three-month A1C measurement, which has been the gold standard for diabetes management since the early 1990s.

While it’s not a replacement for A1C, many diabetes experts and individuals with the condition view this measurement as a more realistic and practical way to gauge their daily management.

This often accompanies use of a continuous glucose monitor (CGM), but time in range — or TIR — may also be used by those who do multiple fingerstick blood sugar checks each day.

TIR essentially shifts away from a single precise measurement of blood sugar to provide people with a sense of how often they are staying within the desired range they’ve decided on with their healthcare team.

It uses continuous glucose monitor (CGM) data to calculate the actual amount of time each day a person with diabetes spends within the desired target range.

This is different from an A1C result, which provides an average of blood sugar levels over the past 3 months or so. The A1C does not reflect change or glucose variability, meaning that a low or high A1C may not show high or low blood sugar levels over several months.

This is problematic, as increasing research indicates variability plays a significant role in overall diabetes management and outcomes, especially over time in terms of diabetes complications.

With TIR, people with diabetes and their care teams can better understand how someone’s management is progressing over time and at specific times of the day.

Examples of A1C shortcomings

The A1C is an important metric in diabetes management. However, it became the “gold standard” in the early 1990s, before CGM technology was introduced and allowed for people to have more complete pictures of their blood sugar data throughout the day and night.

An A1C measurement does not reflect changes in glucose levels. Two people can have the exact same A1C value but spend wildly different amounts of time at high and low blood glucose values.

For example, someone may experience severe low blood sugars (hypoglycemia) every day or overnight when they’re asleep. This may lead to an A1C result being manipulated over time, reflecting a sort of “false low” that doesn’t reflect someone’s accurate picture of dealing with dangerous low blood sugars.

The same may occur if someone has very high blood sugar levels (hyperglycemia) at specific times of the day or night. The A1C may appear higher, not reflecting the specific pattern and allowing them to address that hyperglycemia.

The TIR measurement has become an accepted standard in the diabetes community.

Diabetes clinicians use this measurement, alongside A1C and other data points, to help people with diabetes manage their condition and recognize blood sugar patterns that may require attention.

While it’s a very personal number, many view an acceptable time in range to be at least 70% of the time between 70 to 180 mg/dL.

The American Diabetes Association (ADA) included this in their annual Standards of Care starting in 2019. Over the years, the specific guidance can depend on many factors, including your diabetes type, whether you use insulin, pregnancy status, and age.

Those recommendations include:

  • people with T2D who are on insulin or use glucose-lowering medications should consider CGM technology that may help increase TIR, reduce A1Cs, and lead to fewer high blood sugars
  • CGM tech and TIR measurements may be beneficial when introduced as early as possible in people with diabetes, even at diagnosis
  • glucose targets for older adults also include TIR alongside A1C
  • people who are pregnant also experience benefits from TIR use, whether they are living with T1D, T2D, or gestational diabetes

Beyond its clinical applications and use in everyday life for people with diabetes, researchers are industry are also using TIR more often.

For example, this 2024 research suggests that T2D clinical studies for developing new medications or treatments and tools would see benefits from including the TIR metric along with A1C data.

For example, that metrc may be used in retinopathy research for those who experience this diabetes-related eye compliation and when new treatment options are being developed.

Many diabetes companies are already utilizing TIR when developing new drugs, technologies, and tools and submitting them to the Food and Drug Administration (FDA) for review.

Time in range is an emerging measurement for people with diabetes in their daily blood sugar management.

Using CGM data, this calculates the amount of time you spend in a particular target goal — often 70 to 180 mg/dL.

This is different from a blood sugar average that doesn’t reflect the rest of your glucose levels throughout the day. It’s also different from an A1C result, which is a three-month average that doesn’t reflect variability you may experience each day or night.