How Does a Pedometer Work?

Proper Usage

A pedometer is a device that tracks the number of steps a person takes throughout the course of the day. This small device is often used to help a person meet a set goal of steps taken per day in order to increase the amount of calories burned. While pedometers range in levels of sophistication, they have some basic commonalities in how they count steps.

A pedometer is most often worn clipped to a belt and upright, which facilitates the most accurate reading possible. Correct wear of the pedometer allows it to perform its counting duties.

Data Collection

The number of steps taken daily can be measured by a pedometer in one of two ways. The first is through measuring the movement of the hips. Because when a person walks, his hips are propelled forward in a back-and-forth motion, the pedometer counts every motion a person makes via the hips as a step. Each person may take a different length of stride that can affect the pedometer's measurement differently. For this reason, it's often possible to calibrate the pedometer according to the length of the stride taken and the corresponding hip "bump" this makes to the pedometer.

Another method a pedometer uses to measure steps taken is to count the actual number of times your feet step on the ground. This is usually reserved for more high-tech monitoring devices, such as specialized shoes that transmit steps-taken data to an iPod or other wireless device for measurement. While these pedometers tend to be more accurate than those that simply measure hip movement, they also tend to be significantly pricier.

Measurement Output

Once the steps data is collected, the simplest of pedometers measure this solely in terms of steps walked over a period of time. For example, a person may reset his pedometer at the beginning of a new day in order to reach a steps goal, such as the 10,000 steps per day recommended by the American Council on Exercise.

More sophisticated pedometers may convert the number of steps into additional data. A pedometer calibrated to a person's stride length may use data on a stride length that corresponds to a step and use this number to compute the amount of miles or kilometers walked in a day. Other measurements for conversion include calories burned.

Pedometers can have up to a 50 percent error rate in terms of measurement, which can strongly affect what a person thinks she is walking throughout the course of the day. For this reason, if a person is able to purchase a higher-end or high-quality pedometer, which can be calibrated, the more likely a person is to capture correct data.