What Is Time in Range and Why It Matters More Than A1C

Understanding Time in Range

For decades, the A1C test has been the gold standard for measuring diabetes management. But a newer metric called Time in Range (TIR) is changing the way people with diabetes and their healthcare providers think about blood sugar control.

Time in Range measures the percentage of time your blood glucose stays within a target range — typically 70 to 180 mg/dL — over a given period, usually 24 hours. Thanks to advances in continuous glucose monitors (CGMs) and smart blood glucose meters, tracking TIR has never been easier or more accessible.

How Is Time in Range Different From A1C?

A1C provides an average of your blood sugar levels over the past two to three months. While useful, it has a significant blind spot: it cannot show you the ups and downs happening throughout each day.

Think of it this way — a person could have an A1C of 7% while spending hours swinging between dangerous lows and dangerous highs. Their average looks acceptable, but their daily experience is anything but stable. Time in Range exposes this hidden variability that A1C simply cannot capture.

For example, two people can share the same A1C result yet have completely different TIR scores. One may spend 80% of their day in a healthy range, while the other spends only 40%. The difference in their actual health outcomes can be significant.

Why Time in Range Matters More

Research increasingly supports TIR as a powerful predictor of diabetes-related complications. Studies show that higher Time in Range is associated with:

• Lower risk of diabetic retinopathy (eye damage)
• Reduced likelihood of kidney disease progression
• Better cardiovascular health outcomes
• Improved quality of life and daily energy levels
• Fewer hypoglycemic episodes

The American Diabetes Association now recommends that people with Type 1 or Type 2 diabetes aim for at least 70% Time in Range — meaning roughly 17 hours per day within the healthy glucose window. Reducing time below range (hypoglycemia) and above range (hyperglycemia) are equally important goals.

How to Track Your Time in Range

CGMs are the most convenient way to monitor TIR continuously. However, not everyone has access to a CGM, and structured blood glucose testing with a reliable meter can also provide valuable TIR insights when readings are logged consistently throughout the day.

Resources like mdsdiabetes.com offer expert guidance on choosing the right blood glucose monitoring tools and understanding how to interpret your data effectively. Whether you use a CGM or a traditional meter, consistency in testing is key to building an accurate picture of your TIR.

Practical Tips to Improve Your Time in Range

Improving your TIR doesn't have to feel overwhelming. Small, consistent changes can make a measurable difference:

• Eat balanced meals — Focus on low-glycemic foods that prevent sharp spikes
• Move regularly — Even a 10-minute walk after meals can reduce post-meal glucose rises
• Test more frequently — More data points mean a clearer picture of your patterns
• Work with your care team — Share your TIR data at every appointment for medication adjustments
• Manage stress — Cortisol directly raises blood sugar levels

The Bottom Line

A1C remains a valuable tool, but it tells only part of the story. Time in Range fills in the critical gaps by showing how stable your blood sugar truly is throughout each day. As monitoring technology continues to improve, TIR is rapidly becoming the most meaningful measure of diabetes management — and your most powerful guide to living healthier with diabetes.