FitBit vs. Body Media

This is a guest post from Ted Vickey. Thanks Ted!

As part of my PhD in physical activity, social networking and technology, I have been wearing two devices that have monitored my daily activities – FitBit and Body Media.

Image002 vs. Image006

This post is not about discussing the devices, you can find information about each on their websites. I am interested in comparing the data collected on the same day, doing the same activities.

For April, this is what was collected with regards to the number of steps I took per day:

Each device was worn as suggested per user directions.

In all but two days, FitBit recorded more steps on the day than did Body Media.  The average difference per day was around 589 steps per day, two days showed a greater than 100% difference in the number of steps.

To early yet to determine why.  I will continue to wear both and look at additional data as it become available.

Has anyone else noticed this discrepancy in step measurement? Ted is currently talking to the CEOs of Body Media and FitBit, and will report his findings at the upcoming QS conference.

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27 Responses to FitBit vs. Body Media

  1. Douglas says:

    I noticed a few ‘steps’ with the FitBit counting as more than one in small tests until I dialed in the stride length. Nothing extreme to begin with, but enough that over the course of a day or week would match somewhat your results.

  2. Brendan says:

    I had an Omron pedometer prior to getting the FitBit. The Omron’s algorithm would only start counting steps after 10 or so steps, so movements around the office or even walking around my apartment often didn’t register as any steps at all. I’d also notice that even with a good pace walking in the city that the Omron wouldn’t switch to the more active counting if I was frequently stopping at lights, etc.

    Some days the Fitbit had twice the number of steps, but due to those reasons it always seemed more accurate.

  3. Toli G. says:

    This is in line with my own findings; I’ve measured out the steps on one stretch of road with a few friends counting along, and the FitBit added 10-15 extra steps on average. I’m not too worried about the actual number of steps, I use it to compare my progress in comparison to days past, so I know that at least it will be “faulty” at all times; however, yeah, in terms of accuracy there is something going on.

  4. What were your activities from 4/20-4/22?

  5. Keegan Hall says:

    Overall, I’ve been happy with my Fitbit. I really enjoy seeing my “All-Time Stats” and then trying to beat them. I thought for sure I’d shatter all of my personal records yesterday as I ran the Vancouver Marathon. Due to a race day mix-up (I was sent to the wrong starting line), I ended up running 32 miles (as tracked by my Garmin 405 watch) just on the race course- not counting the long walk to/from my hotel or the other walking I did throughout the day. However, my Fitbit recorded only 32 miles for the ENTIRE day. Bummer. I don’t think I’ll ever have another day like that… :(

    • Ken Taylor says:

      Step count is a poor method of measuring distance as stride length is variable, particularly with speed. Distance measured from step count is better than nothing but not very accurate.

  6. Ted, great analysis on the Fitbit and Body Media. I’m in the process of testing and evaluating multiple devices as well including the ZEO and Fitbit for sleep and others… I’d like to stay dialed into your ongoing research and potentially cover it on

    • Ted says:

      David – look me up on LinkedIn. I have been tracking sleep as well since Christmas using BodyMedia and for a few weeks with FitBit.

  7. Jolly says:

    BodyMedia seems to have better accuracy, fitbit is nicer to use, I prefer their website, and the wireless syncing functionality. (I’m selling my BodyMedia)

    Fitbit is far too easy to lose – put it on a lanyard!

    Zeo trumps both for sleep tracking.

  8. Eric says:

    You can get a PhD in “physical activity, social networking and technology?!” I don’t know whether to be happy about that or to shoot myself in the face.

  9. Tim says:

    I ran the 21 miler at the Big Sur Marathon on May 1 – Fitbit registered 25 miles. However, when I tested fitbit on several treadmills for shorter distances it was spot on. I suspect my stride shortens on longer distances as I get into the marathon shuffle, taking more steps per mile than usual.

  10. George says:

    Fascinating study. Thanks! I find that the BodyBugg provides me with more information that is useful to my overall health, or rather calculates certain information based on a wider range of data, such as body temperature and galvanic response. I’m looking forward to the MyBasis device though, as I’m hoping that it will provide even further data that BodyBugg does not, i.e. sleep information and heart rate. My main concern with most of these devices is that there are specific devices for each specific case. Given the appropriate number of sensors, the rest should be taken care of in software. I don’t like having one device to measure steps, the other to measure heart rate, and yet another to measure my sleep habits. It should all be one, and syncable to a web site and my phone. Having options to wear it as an arm band or as a watch is also good.

    Ok, rant over. Thanks again for the study!

  11. It will, however, track just how active you are, on average, on any given day, upload that data through a wireless base to the website, and organize the information into nifty pie charts, bar graphs and averages tracked over time to give you an idea of your overall fitness level. In short, it’s a pocket-sized fitness coach that won’t yell at you if you skip your 5 AM walk.Fitbit Review

  12. Lauren B. says:

    This is great – thank you! Do you happen to have a comparison of calories burned for each device? I’m assuming that Body Media is probably a more accurate reading since it measures body heat, etc.? I would like to buy the body media, but like how much easier it is to wear. Any thoughts?

    • Fe says:

      Body Media is very accurate. I have been so used to wearing it. And yes, I learned that there are a lot of inquisitive people around because you do have to wear it on your arm. I only take it off when showering or bathing or recharging. Other than that, I use it all day. It tracks sleep habits, calorie burn, steps, and you can log food. I only which it was wi-fi. So now I am looking for something that is just as great and accurate with wi-fi.

  13. Alan says:

    I use my fitbit on the same route and get almost the same step count everytime. It varies by about 10-100 steps on a 12,000 step course. Which could be taking a slightly tighter angle on a corner, or being forced around an object.

    I go up and down 20 flights of stairs and get the exact amount of stairs on the step count, so very happy there.

    I have only had false readings twice. The unit is suseptible to mistaking shaking for stepping. So on a RollerCoaster ride I clocked up over a thousand steps for just stepping onto and off the ride. Another time was sitting on a lawnmower and mowing the lawn I clocked up 18,000 steps.

    Sleep readings are spot on too. I have been to the sleep clinic and they use a similare device and the fitbit sleep reading was indenticle. Not bad for $99
    Really looking forward to my new Ultra

  14. Ted Vickey says:


    I saw the press release on the Ultra last week. Looks interesting. I use the Zeo for my sleeping, but that could be a great follow-up post comparing BodyMedia to the Zeo. Never used the FitBit for sleep measurement (yet).

  15. Mandy says:

    i knw this post is kinda old, but i have bought the bodymedia armband for $150,and have used it only 2 days. the accurancy is awesome but my problem is cannot wear it everyday because of my job…dont want ppl keep askin me what it is…trying to sell it.anyone know how or where can i sell this? or anyone here needs it? for $100?

    • Lou Ann says:

      Wondering why you can’t wear it everyday. First – who cares if they ask. Once you tell them there is no need for them to ask again – eventually people will stop asking. I wear dress clothes and sometimes you can see the outline under a sweater. I sometimes turn the bulky part to the inside of my arm so it’s not noticeable to others.

    • Patty Peshek says:

      During the day, I wear the devise in my bra on the side. I’ve used it for a couple of years. I’ve compared the calories burned with my regular hr monitor. Very accurate wearing it there.

  16. Andrea says:

    Mandy, I decided that I was just going to deal with the comments – I mean, who cares? You’re doing something for YOU. It’s like asking someone about their new smartphone or their fancy shoes – something you can either brush off or FLAUNT.

    I wore a BodyMedia for a full year, only taking off in wet conditions (including hot yoga). I “grew” an arm dent from the squeeze so I shifted to the other arm with no change in measurements that I could tell.

    I sold it, am now thinking about fitbit because it is so tiny and has wireless sync. I mostly want to count/track/incentivize my steps instead of measure everything.

  17. Roger says:

    I went from the omron to the fitbit and back to Omron. Fitbit over counted by steps all the time.

  18. Lynn Hearn says:

    I’m wearing two to three Omron pedometers and they are within 5 percent. The Fitbit consistently registers far higher steps. I think Fitbit give faulty readings.

  19. LeeAnn says:

    Have had the bodymedia for 6-7 months. It seems that a good pedometer registers steps just as well. I find the arm band to be uncomfortable too.

  20. lindsey says:

    Hey, so I am trying to decide which product I want to buy. Which did you enjoy using the most interms of website and how easy they were to use?

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