All modern pedometers work on the same basic process of measuring an electronic pulse generated by each step the wearer takes to count the number of steps taken. Some advanced models use this and other information to provide more detailed readings.
In order for a pedometer to count the number of steps taken by its wearer properly, it must assume certain facts as standard for that person. For example, each step a person takes is assumed to be approximately the same length. By standardizing the length of each step, also known as the stride, the pedometer can perform a uniform calculation for all strides, instead of attempting to measure or compensate for half-steps and larger steps.
Once the pedometer is programmed with the wearer's average stride length, it uses a small electronic pulse generated by the force of the body tilting during each stride to count the step. Older models worked on a more mechanical basis that required a greater amount of energy to count each step, but they were often inaccurate as a result.
High-end pedometers contain features that extrapolate further information for the wearer based on the number of steps taken. By entering the wearer’s age, weight and height, the pedometer can calculate the number of calories that person burns with each step.