When I carry my iphone with me my Blaze records a significantly less number of miles why?

[HondasGirl]

Today I forgot my iphone10 on my daily walk. I was surprised to find that my blaze recorded what my husband has been saying all along was the correct mileage because he has a Garmin 920XT and uses Strava. 

So now we are both wondering why when I carry my phone what would cause my blaze not to calculate the correct mileage?

I have the Fitbit app loaded on my iphone10.

[Rich_Laue]

Hi @HondasGirl when you go for a walk, do you use the phones GPS and get a map? Does the map look correct? 

Without the phone, your blaze took a guess at the distance by using your step count and stride setting. 

With GPS Fitbit uses a combination of GPS points and stride. 

Why the difference, I'm not sure. 

[HondasGirl]

I use my phone for navigation all time so I know GPS is on. I do not open the fitbit app when I am walking with my blaze and phone so I assume it's using the GPS.

When you say check the Map do you mean within the Fitbit app or just in general like checking google maps?

[Rich_Laue]

Yes, the map of your route found in the Fitbit app