Fitbit: 50 floors in one day!

I'm really trying to up the time and intensity of my walking. Today I walked to the store, back, then to campus! I knew there were some hills and inclines to go up. However Fitbit measures things it was 50 floors today! 15,152 steps taken today. (I've done over 15K steps 36 times on the days I've worn the Fitbit.)

Fitbit = I've clocked in 15,152 steps, 6.33 miles, (lightly active 2:27, fairly active 1:46, very active 30 min (total 4.43 hours)), burned 2080 calories

With the phone Moves = I've clocked in 12,821 steps, 6.3 miles, 2:15 hours active, burned 508 calories.

So the difference is time without the phone and just differences in the two systems of measuring.  I'll try to keep the phone with me all day tomorrow just to see how the numbers go.

It's windy and hot.