I HATE to burst everyone bubble on this but MOST pedometers are contact oriented. In other words it feels the contact of a footstep and measures a step (avg 3ft). I know at WDW a pedometer would generate a lot of false steps like waiting in line and the steps you take there are maybe half a foot or a foot in length. Also bumps on rides and etc would also register false steps.
I’LL tell you what my mousebuzz friends - In march I will wear my garmen running watch (GPS in it) and get a real accurate count of our average walk distance in a day. I will have to remember to turn it it off on rides, but it will be real close to perfect.
If I had to guess on a full day basis - EPCOT is about 6 - 8 miles in a day, MK would be about 5 or 6, AK would be about 4 or 5, and HS about 3 to 5. I know AK is smallest but I find myself walking alot in that park for its size.