How to Calibrate a Pedometer Using a GPS Unit

A good pedometer will offer a feature that tells you the actual physical distance you've traveled. But the pedometer is really only capable of counting steps. It estimates distance by multiplying the steps you take by an average stride length that you give it. It's very hard to determine a proper stride length by simply measuring your steps. But with a GPS unit to determine actual distance traveled, you can quickly calibrate your pedometer to give you accurate results.

Things You'll Need

• A Pedometer that estimates distance traveled based on your stride length, A GPS unit

Instructions

1. Learn how to track distance on your GPS unit. Any good GPS unit should be able to tell you how much distance you've traveled from a starting point regardless of how many twists and turns you take. But the specifics will depend on your unit. Check the manual, figure out how to find the distance reading and zero out any previously stored information.

2. Enter a stride length on your pedometer. Most pedometers let you enter quite a wide range for this value, from one foot up to as much as four feet. Give it your best guess or, if you really have no idea, just pick a number in the middle of the range like two feet, six inches.

3. Start the distance measurement reading on your GPS unit and start walking. You want to walk a pretty good distance: at least a mile and preferably more. The more steps you take, the more reliable your average will be. If possible, try to walk on level ground as steep slopes will cause the length of your steps to vary.

4. Check the pedometer against the GPS unit. Once you've completed your walk, check the GPS unit to see how much distance you actually covered. Then check the pedometer's estimate. If they agree, or if they're just really close, then you made a lucky guess about your stride length. But your pedometer will probably be wrong. If the pedometer says you went farther than the GPS unit, then the stride length you entered is too long. On the other hand, if the pedometer says you didn't go as far as the GPS unit says, then the stride length you entered is too short.

5. Adjust the average stride length on your pedometer and try again. Based on what you learned from your first walk, tweak the pedometer's average stride length setting up or down and go walking again. This time you should be closer. Once you get the pedometer to agree with the GPS unit, or at least within a couple decimal places, then you've got your pedometer properly calibrated. Now you can go walking without the GPS unit, or just let distance accumulate as you walk around during the course of your day, and rely on the distance figure your pedometer gives you.