Finding an Accurate Pedometer for Counting Your Steps

How accurate is your pedometer? Are you really walking 10,000 steps per day? Pedometers have undergone rapid evolution from designs that used spring-lever and pendulum mechanisms (readily available in the mid-1990s) to those that use a piezo-electric mechanism, and to accelerometer chips built into mobile devices and fitness bands starting in 2010.

Pedometer Accuracy

Spring mechanisms used in some pedometers are affected by tilt, while dual-axis and tri-axis accelerometers are not. Pedometers with dual-axis and tri-axis designs can be worn in a wider variety of positions.

Pedometers have been shown to not be accurate when people walk at a very slow pace. However, a 2019 study concluded that "particularly at slow gait speeds, relevant improvements in accuracy have been achieved" with recent technology.

According to a study published in 2015, tri-axial piezo-electric pedometers tested less accurate when carried in a pocket and when walking at very slow speed or very high speeds. They were generally accurate within 5% (which is 500 steps in a 10,000-step total) when worn on the waist, lanyard, or armband while walking at a moderate pace.

Fitness Tracker Accuracy

Step tracking has largely moved past non-connected pedometers worn on your waistband to app-connected activity monitors, especially those worn on the wrist. However, which of these is accurate is a moving target as they continue to evolve.

Manufacturers can improve their accuracy by studying the data and revising the algorithm that translates the movement they sense into steps. They can then update the software of the device rather than the user having to buy a new device. Or, in lieu of a separate tracker, many people simply use the data they can get from their mobile phone's built-in accelerometer.

Step-Count

A small 2017 study pitted the Fitbit Charge and Smart Health wristbands against an Omron HJ-303 waistband accelerometer and a Sportline spring-lever model. In their short treadmill test, researchers counted steps taken via video and manually counted with a clicker to compare with what the units registered. The Fitbit Charge was the least accurate, followed by the Smart Health wristband, then the Omron, and finally the Sportline—which uses the oldest technology.

However, another small but similar study, this one from 2018, validated the step-counting accuracy of the Fitbit Surge and the now-discontinued Microsoft Band 2 (but not the Fitbit Charge HR).

Calorie-Burn

A 2014 study of the accuracy of activity monitors and fitness bands in estimating calories burned found that the best of them (BodyMedia FIT, Fitbit Zip, and Fitbit One) were about 90% accurate. The study compared those three devices along with Nike FuelBand, Jawbone UP, Basis B1 Band, and others.

A 2018 study comparing the Fitbit One, Fitbit Zip, Fitbit Flex, and Jawbone UP24 with a research-grade accelerometer (the ActiGraph) found the inexpensive, commercial devices to be about as accurate as the ActiGraph in tracking both physical activity (steps and active minutes) and energy expenditure (calories burned). Most of these devices are no longer produced, but Fitbit still has several other watches and trackers on the market.

Heart-Rate

Many wrist-worn fitness trackers also measure heart rate. A small study published in 2019 compared two wrist trackers (the Polar A370 and the inexpensive Tempo HR) with a chest-strap tracker (the Polar H10). Both wrist trackers were "reasonably accurate," but as heart rate increased, so did inaccuracy, especially in the Tempo HR device.

A Word From Verywell

Activity tracking tech is not yet perfect, but it's constantly evolving and improving. While a fitness band, app, or smartwatch may not give you exactly accurate step count details, it still gives you a good idea of your activity level, and a way to compare your day-to-day performance and incremental improvement (competing against yourself). If you find wearing a fitness tracker motivating, keep it up.