A:AnswerI purchased the Alta, bigger screen and a nice piece , big screen and not so user friendly, it’s more of a smart watch like I watch
The 3.. very good Fitbit, self contained, very user friendly and easy to read. Not as much frills as the versa . Not to mention the price !! 3 is way cheaper but, whatever your preference really!!
A:AnswerIf it's possible it should be done through the app. But I believe it's based on weight & height and the calories you burn and the amount of your activities.