When you go to enter how much exercise you've done that day, it asks what kind, how vigorous, and how long. Below those questions it should say how many calories you've burned :-) on your home screen, when you push the + sign, you'll get to the option that says "exercise" just tap that and you'll get to the page I just told you about :-) I hope this helped :-) stay beautiful :-)
Not quite sure if you even can. I've been using an app called "Calories Burned Calculator" and just plugging in the number it gives me.