There are many apps available today that coordinate with not just the iPhone, but can also pair with your Apple Watch as well. The short answer is: it can, but you’ll need to get an app for that.
If you’re really trying to keep track of your calories throughout the day you can set the face of your watch to display: Your Apple Watch has an activity tracker ready and available. This exercise will help your Apple Watch understand your pace, acceleration, stride, and thus refine the calculations of your calorie burn. You’ll then walk at your regular pace for 20 minutes. Open the Workout app, and choose “Outdoor Walk” as your activity. It’s important to have excellent GPS signal during the calibration process.
To do this, take it and your iPhone outside on a nice clear day. You’ll also want to calibrate your Apple watch. You’ll want the heart rate sensor to be snug against your skin, but of course, make sure you still have feeling in all of your fingers! Make sure you don’t put your watch in Power Save Mode during your workout, either, or that will turn off the Heart Rate Monitor feature.
Next, make sure your watch is tight enough.
