Do you have any idea how many steps per day (on average) children and teens take? Some researchers were interested in this question and combined pedometer data from students in grades 1 through 12 (mostly from the southwest United States). Their results are presented below. For simplicity, the researchers grouped grades together.

Reprinted, by permission, from G.C. LeMasurier et al., 2005, "Pedometer-determined
physical activity levels of youth," Journal of Physical Activity and Health 2(2): 153-162.
As you can see, young children accumulate more activity than older children. Why do you think that is? Also, males accumulate more steps per day than girls. Do you have any ideas about this finding?
Other researchers (Tudor-Locke et al., 2004) have shown that if girls take at least 12,000 steps per day they are less likely to be overweight and obese. Boys who accumulate at least 15,000 steps per day are less likely to be overweight or obese.
If you plan to start a walking program with a pedometer, don’t worry too much in the beginning about how many steps you’re getting. Just see how many steps you get in a week and determine your average steps per day. Once you know your average steps per day, you can make a goal that is specific, measurable, attainable, realistic, and tangible (SMART). Keep setting goals and achieving them, and before you know it you’ll be as active as you need to be for good cardiovascular health and body composition.
Le Masurier, G.C., Beighle, A., Corbin, C.B., Darst, P.W., Morgan, C., Pangrazi, R.P., et al. (2005). Pedometer-determined physical activity levels of youth. Journal of Physical Activity and Health, 2(2), 153-162.
Tudor-Locke, C., Lee, S.M., Morgan, C.F., Beighle, A., & Pangrazi, R.P. (2004). Sex-specific activity patterns of the segmented school day. Research Quarterly for Exercise and Sport, 75(1 Suppl.), A-32.