Here's how inaccurate your phone's step counter could be

Here's how inaccurate your phone's step counter could be

Your phone can measure your movements but overestimates your daily steps.

Photo credit: Getty Images

Published: October 7, 2023 at 2:00 pm

Your phone uses GPS to track distance travelled. But try disabling it and you’ll notice that fitness apps will still give you step counts. They do this using your phone’s built-in sensors, which usually include an accelerometer and a gyroscope.

Accelerometers measure acceleration, while gyroscopes help track the direction your phone is pointing in, usually by measuring the movements of tiny components inside them that generate electric signals as they move. According to the experts, the best place to count steps is at the hip and so putting your phone in your pocket should provide a more accurate count than putting it in your bag. 

A study published last year tried to verify the accuracy of smartphone apps for step-counting, comparing results from a medical-grade accelerometer worn on the hip to those from the WeRun app. 103 people used both at the same time, for three, week-long bouts of step-counting. The study showed the app overestimated the average daily step count of around 8,500 steps by close to 500 steps

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Asked by: Amy Webster, age 15 via email

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