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

If you have been managing diabetes for a while, you have probably had A1C drilled into your brain as the single most important number. But there is a metric that many endocrinologists now consider even more useful for day-to-day management: Time in Range.

Time in Range, Explained Simply

Time in Range (TIR) is the percentage of the day your blood glucose stays within a target zone. For most people with Type 1 or Type 2 diabetes, that standard target is 70 to 180 mg/dL (3.9 to 10.0 mmol/L). If your glucose is between those numbers for 18 out of 24 hours, your TIR is 75%.

The beauty of TIR is that it is intuitive. Instead of a single lab number drawn every three months, you get a living, breathing picture of how your glucose actually behaves throughout the day. You can see it shift week to week, or even day to day, depending on what you eat, how you move, and how you dose.

Your target range can also be customized. Pregnant individuals often aim for a tighter window of 63 to 140 mg/dL, while some doctors loosen the range for older adults or people prone to severe lows. The key is that TIR is flexible enough to reflect your goals, not just a population average.

Why Endocrinologists Are Shifting Away from A1C

A1C has been the gold standard since the landmark DCCT trial in the 1990s, and it is not going away. But it has real limitations that TIR addresses.

A1C is a weighted average of your blood sugar over roughly 90 days. The problem with averages is they hide the extremes. You could have an A1C of 7.0% while spending half the day at 200 and the other half at 50 — that average looks "fine," but your actual experience is a rollercoaster of highs and lows that wreck how you feel and carry long-term risk.

TIR, on the other hand, captures the variability. Two people with an identical A1C can have wildly different Time in Range numbers. The one with steady, in-range glucose and minimal swings is almost certainly at lower risk for complications and feeling a whole lot better day-to-day.

The Consensus Targets: What to Aim For

In 2019, the ADA (American Diabetes Association) and ATTD (Advanced Technologies & Treatments for Diabetes) published joint consensus recommendations for CGM-based targets. These have since become the standard reference:

• TIR above 70% (70–180 mg/dL) for most adults with Type 1 or Type 2 diabetes
• Time below range under 4% (below 70 mg/dL) and less than 1% below 54 mg/dL
• Time above range under 25% (above 180 mg/dL) and less than 5% above 250 mg/dL

A TIR of 70% roughly corresponds to an A1C of about 7%, which helps bridge the two metrics in conversations with your care team. But TIR gives you something A1C never could: a target you can actually influence in real time.

How to Check Your Time in Range

If you wear a continuous glucose monitor (CGM) like a Dexels G7, Libre 3, or Medtronic Guardian, your sensor app probably shows TIR somewhere in its reports. The challenge is that these reports can be buried in menus and are often designed more for clinicians than for you.

That is where a companion app helps. SweetLife, for example, shows your Time in Range right on the home screen so it is the first thing you see when you open the app. The Insights tab breaks it down further, showing trends over 7, 14, and 30 days so you can spot patterns and see whether changes you have made are actually working.

Even if you do not have a CGM, you can get a rough TIR estimate from fingerstick readings, though it will be less precise since you are sampling discrete moments rather than a continuous stream.

Practical Tips to Improve Your TIR

Knowing your TIR is step one. Improving it is where things get interesting. Here are strategies that consistently help:

Take a post-meal walk

Even 10 to 15 minutes of light walking after eating can blunt a post-meal spike significantly. Your muscles pull glucose from the bloodstream during activity, and the effect is surprisingly powerful. It does not need to be intense — a stroll around the block counts.

Pre-bolus if you are on rapid-acting insulin

Dosing insulin 10 to 20 minutes before you eat (rather than right when you sit down) gives it a head start on the carbs hitting your bloodstream. This single habit can shave the top off post-meal spikes and add meaningful percentage points to your TIR. Talk to your endo about safe timing for your situation.

Avoid insulin stacking

When you see a high number, the temptation is to rage-bolus a correction on top of insulin that is still active. This often leads to a crash two hours later, swinging you from above range to below range. Most insulin-on-board calculators are your friend here — trust them.

Pay attention to overnight patterns

You spend roughly a third of your day asleep, so overnight glucose has an outsized impact on your TIR. If you are consistently going high or low while sleeping, adjusting basal rates or long-acting doses (with your doctor) can move the needle dramatically.

Focus on consistency over perfection

You do not need a TIR of 100%. Nobody has that. Even 70% means you are in range for nearly 17 hours a day, which is genuinely great management. Small, sustainable changes beat dramatic overhauls that you abandon after a week.

Bringing It All Together

Time in Range is not a replacement for A1C — it is a complement that gives you a richer, more actionable picture of your glucose management. A1C tells you where you have been over three months. TIR tells you how you are doing right now and helps you figure out what to change next.

The shift toward TIR is one of the most positive developments in diabetes care in years. It puts more power in your hands, rewards the daily effort you are already putting in, and gives you a number you can actually move with real-world decisions.

Whether you are newly diagnosed or have been at this for decades, paying attention to your Time in Range is one of the best things you can do for yourself. And the best part? You do not need to wait three months for a lab to tell you how you are doing.