When you use one of FreeStyle Libre systems^* for monitoring your glucose levels, you will be able to see your current glucose reading, a graph of your recent glucose readings, your target glucose range and a glucose trend arrow. The arrow points in the direction your glucose is heading.

Together with your current glucose reading, Trend Arrows can help you decide whether or not you need to take action. This may be taking a corrective dose of insulin, if that’s what your Healthcare Team has advised.^†

To work out your estimated glucose levels, you need two calculations:

Let's work through an example:

You have a glucose reading of 6.5mmol/L and an upward trend arrow and you want to know where your glucose level will be in 15 minutes. 

First, you need to use the rate of change to find out how much your glucose level will change in 15 minutes. You’ll do two calculations here — one for the upper rate of change and one for the lower rate of change.

Next, we’ll use these numbers to calculate your estimated glucose level in 15 minutes’ time. Because your trend arrow is trending upwards, you add together the current glucose reading and change in glucose level. If your trend arrow is trending downwards, you subtract the change in glucose level from the current glucose level.

Again, we’ll do the same calculation for both the upper and lower rate of change.

Now you know that in 15 minutes’ time, your glucose level will be somewhere between 7.4mmol/L and 8.0mmol/L.