Setting up the iPhone's pedometer
This is done in Settings>Privacy>Motion & Fitness — just visit that page and toggle Fitness Tracking on. Now your iPhone will count your steps.
Is there a pedometer on my iPhone?
Your iPhone has a built-in step tracker to help you stay in shape and make sure you get your 10,000 daily steps in. You don't have to turn this feature on; your iPhone is already tracking your steps by default.
Where do I find my step count on iPhone?
To check this information, open the Health app and go to the 'Health Data' section. Tap Activity and you'll see information about how many steps you have walked, how many flights you've climbed, standing, running and so on.