Most people with diabetes know their HbA1c number. It’s the three-month average that doctors use to judge how well blood sugar is controlled. But here’s the problem: two people can have the same HbA1c and be living completely different diabetes experiences. One might feel fine, never crash low, and sleep soundly. The other might spike to 250 after lunch, dip to 55 at night, and never know it until they’re dizzy or exhausted. That’s because HbA1c hides the daily rollercoaster. This is where time in range changes everything.
What Exactly Is Time in Range?
Time in Range, or TIR, is simple: it’s the percentage of time your glucose stays between 70 and 180 mg/dL (3.9-10.0 mmol/L). That’s your sweet spot. If you’re in that zone 70% of the day, you’re hitting the target most experts agree on. That means about 17 hours out of 24, your blood sugar isn’t too high or too low. It’s steady. It’s safe. It’s sustainable.
This isn’t guesswork. It comes from continuous glucose monitors (CGMs) that check your glucose every 5 minutes-over 2,000 readings in just 14 days. That’s way more data than a finger prick or a lab test ever gives you. And it’s not just about the average. TIR shows you exactly when and why your numbers move. Did your blood sugar spike after that avocado toast? Did it drop after your evening walk? TIR tells you.
Why TIR Beats HbA1c for Daily Life
HbA1c is like reading the last page of a book. You know how it ended. But you don’t know the plot twists. TIR reads the whole story.
Take two people. Both have an HbA1c of 7.0%. Sounds good, right? But one spends 85% of their day in range. The other? Only 55%. That second person is spending 4 hours a day above 180 and over an hour below 70. They’re at higher risk for nerve damage, vision problems, and dangerous lows-even though their HbA1c looks perfect.
Studies show that for every 10% increase in TIR, HbA1c drops by about 0.3%. But the real win isn’t just the number. It’s the peace of mind. You stop guessing. You stop panicking. You start making smart, real-time choices.
How CGM Turns Data Into Action
CGMs don’t just measure glucose-they reveal patterns. Look at your daily graph. See those sharp spikes after meals? They’re not just numbers. They’re clues. Maybe it’s rice, or fruit juice, or even stress. One patient in Adelaide noticed her glucose jumped every time she drank almond milk. Turns out, the added sugar in the “unsweetened” version was the culprit. She switched brands. Her TIR went from 62% to 81% in 3 weeks.
Or maybe you’re active. You walk 30 minutes after dinner, and your glucose drops 40 points. That’s gold. Now you know exactly what works. No more “I don’t know why I feel tired.” You have proof.
CGM also catches silent lows. You might not feel dizzy, but if your glucose hits 63 at 3 a.m., your body is still stressed. Over time, that increases your risk of heart problems. TIR flags that. You can adjust your nighttime insulin or eat a small snack. Simple. Effective.
What Counts as a Good TIR?
The international standard? At least 70% time in range (70-180 mg/dL). That’s the goal for most adults with type 1 or type 2 diabetes.
But there are other numbers that matter too:
- Time Below Range (TBR): Less than 4% of the day below 70 mg/dL. That’s about 55 minutes. If you’re hitting 8% or more, you’re at risk for dangerous lows.
- Time Above Range (TAR): Less than 25% above 180 mg/dL. Ideally, you want this under 15%.
- Severe hypoglycemia: Less than 1% below 54 mg/dL. Any more than that is a red flag.
Some people aim even tighter: 70-140 mg/dL. That’s called “time in tight range.” It’s harder to maintain, but studies suggest it may lower long-term complication risks even further. It’s not for everyone-but if you’re motivated and have support, it’s worth exploring.
Real Barriers-And How to Overcome Them
CGMs aren’t magic. They cost money. Sensors can itch. The data can feel overwhelming.
Insurance is still a hurdle. In the U.S., Medicare now covers CGMs for type 2 diabetes patients on certain medications. But in Australia, access is patchy. Private insurance helps, but not everyone has it. If you’re struggling to get one, talk to your diabetes educator. They know programs, subsidies, and trial options.
And the learning curve? Real. The first week with a CGM feels like drinking from a firehose. Glucose trends, arrows, alerts-it’s a lot. But you don’t need to understand it all at once. Start with one thing: “Am I in range 17 hours a day?” Then look at meals. Then sleep. Then activity. Small steps build confidence.
Most clinics now offer structured TIR education. The Association of Diabetes Care & Education Specialists (ADCES) has clear tools for patients and providers. You don’t need to figure it out alone.
What’s Changing in 2026?
The American Diabetes Association’s 2025 Standards of Care were a turning point. For the first time, they said CGM should be considered for all adults with type 2 diabetes-not just those on insulin. That’s huge. It means millions more people can now access this data.
In Australia, adoption is rising. CGM use among Medicare beneficiaries with type 2 diabetes jumped from 15% in 2019 to over 40% by 2023. More doctors are talking about TIR. More pharmacies are stocking sensors. More apps are making it easier to share data with your care team.
Future tools? AI that tells you, “Your glucose spikes after pasta, but not after quinoa. Try swapping one meal this week.” Or sensors that last 20 days instead of 14. Or non-invasive patches that don’t need needles. The tech is moving fast.
Your Next Step
Don’t wait for your next HbA1c test to find out how you’re really doing. If you’re managing diabetes with pills, insulin, or just diet and movement-ask your doctor about CGM. Ask about your TIR. Ask for help interpreting the data.
And if you already have a CGM? Look at your report this week. Not the HbA1c. Look at your TIR. Where are you losing time? What’s causing the spikes? What’s helping you stay steady?
Diabetes isn’t about hitting a number. It’s about feeling steady, safe, and in control. Time in range doesn’t just measure glucose. It gives you back your life.
What is the ideal Time in Range percentage for most people with diabetes?
The recommended target for most nonpregnant adults with type 1 or type 2 diabetes is at least 70% of the day spent between 70 and 180 mg/dL (3.9-10.0 mmol/L). This aligns with the American Diabetes Association’s 2025 guidelines and corresponds to an HbA1c of about 7%. Individual goals may vary based on age, health history, and risk of hypoglycemia.
How does Time in Range differ from HbA1c?
HbA1c gives a three-month average of blood glucose, hiding daily highs and lows. Time in Range (TIR), measured by CGM, shows exactly how much time you spend in, above, or below your target range each day. Two people with the same HbA1c can have very different TIR values-meaning one might be at high risk for complications even if their HbA1c looks good.
Do I need to use insulin to benefit from CGM and TIR?
No. While CGM was originally recommended for insulin users, the 2025 ADA Standards now say CGM should be considered for all adults with type 2 diabetes-even those taking oral medications or GLP-1 agonists. Many people on metformin or semaglutide see big improvements in TIR and fewer highs by adjusting meals and activity based on real-time data.
How long do I need to wear a CGM to get useful TIR data?
For accurate results, wear the CGM for at least 14 days with at least 70% active monitoring time. That means no more than 3-4 hours per day without data. A full two-week period gives you a clear picture of your patterns across weekdays, weekends, meals, and activity levels.
Can Time in Range really reduce diabetes complications?
Research strongly suggests yes. Higher TIR is linked to lower risk of eye, kidney, and nerve damage. While long-term studies are still ongoing, data from the T1D Exchange Registry and other large cohorts show that every 10% increase in TIR reduces complication risk. Experts now believe TIR is a better predictor of long-term health than HbA1c alone.
What should I do if my TIR is low?
Start by reviewing your daily trends. Look for spikes after meals, drops after exercise, or overnight lows. Keep a simple log: what you ate, when you moved, and how you felt. Talk to your diabetes educator or doctor-they can help you adjust meal timing, carb intake, or medication. Small, consistent changes often lead to big improvements in TIR over time.
