Pedometers are simple devices that use an integrated circuit and a built in motion sensor to count the steps you take while wearing one. They are best worn on the hip for accuracy as this conveys the motion of your walking directly to the pedometer. What about pedometer accuracy? Although pedometers are never 100% accurate the best ones are around 95% accurate. A cheaper pedometer will usually be less accurate as they may record steps as you move your body even when you are not actually walking. The motion sensor in the more expensive models is much more accurate an records motion by sensing vibrations as you step and your feet hit the ground rather than side to side motion as the cheaper ones do. Read more at How Accurate is a Pedometer?