A bit ago I stumbled upon a really cool tool that allows you to determine your Garmin ANT+ footpod calibration factor based on existing run data that you might have already run with your footpod. For example, if you’re like me – you’ve probably got a few pairs of shoes you probably rotate your footpod around on each shoe depending on a variety of factors. The problem with this is that each time you adjust the footpod location on the shoe – it affects the footpod calibration. In most cases for outdoor running it’s not a huge issue, as the GPS on the Garmin Forerunner units is used by default, with the footpod merely providing cadence or in the event of GPS loss – data for that missing segment. But if you do quite a bit of treadmill running, or if you just happen to use the footpod over GPS, it’s important to ensure the two are aligned. Now for me going to the treadmill and/or the track to perform another calibration test is a bit of a PITA…so I tend not to do it as often as I probably should after I change footpod shoe positions. Thus, in the semi-rare cases where I do end up on a treadmill, the speed may not be correct unless I first re-calibrate it for the new position. And I usually only do that if I’m going to be doing multiple treadmill runs (i.e. – travelling overseas in certain problematic cities where running outside would be heavily frowned upon). Thus, I introduce you to the Garmin Footpod Calibration Tool – which looks at your existing Garmin TCX files that contain both GPS and footpod data, and calculates what you should set your calibration factor to manually. 
The tool is super easy to use. When you open it up, it’ll automatically read in all of your running files from all of your watches. In my case…that’s a lot of watches…and a lot of files. In my case because I’m often swapping shoes/watches/footpods for reviews (and not re-calibrating), the data is a bit more mixed up. For most of you, you probably have a bit more steady data with just one watch and one footpod that’s likely correctly calibrated. Nonetheless, check out the massive list of files for just the past year that it pulled in: 
This list of files shows up in the application on the left side in a column, sorted by date – but also displaying distance as well. When you click on a given activity, it displays more information about that run on the right hand side. 
For those activities that have lap markers in them, you can then expand it to see how the accuracy varies per lap. For example, if you’re doing intervals you may find that on some laps where you’re ‘walking’ you may have higher/lower accuracy that those at faster paces. 
In the above examples where the mileage is .3 – these are lower intensity ‘rest’ periods done at a jog pace – thus you see slight differences in accuracy compared to other paces. That said, I’m 99% sure the unit wasn’t calibrated at the time, hence the larger accuracy shift than I would have preferred. On the right hand side of the application you’ll see two graphs that plot GPS accuracy over footpod accuracy (top chart), and then plot scale factor based on the GPS distance (bottom chart). 
Perhaps more important though is the calibration suggestion/correction portion. This data area displays the new suggested calibration factor should be based on the data from that particular run. In this case, it sees a default factor of 1000 (but you can change that based on your watch) and then the actual distance based on the data in the file. 
If you’re super geeky, you can go into expert mode, which lets you look file by file and section by section at the deviations for each run and the differences between them. 
Pretty cool stuff, huh? To adjust your manual calibration factor on your watch based on the tool you’ll simply go into the footpod settings area on the watch and then to manual calibration. Each one of the Garmin Forerunners has this in a slightly different place – but for most of them its in the unit settings section. The best part here is that the little app is free – developed by Jonathan Savage, and downloadable here. Note that the app is not made by Garmin, but rather just an enthusiastic runner in the community. But technically speaking it’s giving you the exact same data that you would manually insert into the ‘manual calibration factor’. A key item to remember here is that the calibration tool is using GPS data to provide the footpod calibration factor, which is never going to be as accurate as an absolute distance such as 400m/800m on a track. And while GPS accuracy in a track environment can be quite close (as my recent tests have shown), it’s just something to keep in mind if you choose to use the calibrate tool over a track test. For most of us (or maybe just me), I’ll gladly take the time savings over having to run to the track to re-test. Especially given how close the accuracy factor is. Also keep in mind that in some of the screenshots above that I created you see vast difference in accuracy from footpod to GPS. Remember again that I rarely calibrate the footpod myself since I’m changing it so often. But in the past when I do remember to calibrate I’ve shown how astoundingly accurate it can be – especially on the newer units with the newer footpods. This goes for both Garmin and Polar. I’ve gone out and had long interval runs literally exactly the same (GPS vs footpod) – despite being in crazy conditions like snow. 
With that, go download and enjoy the tool, and thanks for reading! – Other resources I’ve put together that may be of interest for those footpod fancy: Garmin ANT+ Foot Pods- Everything you ever wanted to know If you’re looking for literally over 40+ questions and answers on the footpod, I put together this post earlier this year that goes super in depth on the topic. I’m pretty sure there’s no footpod left unturned. 2011 Sport Device GPS Accuracy In Depth- Part I / 2011 Sport Device GPS Accuracy In Depth- Part II These recently published tests I put together talk to the GPS accuracy side of the house, allowing you to consider what types of scenarios terrain-wise you may want to use GPS data from to calibrate your footpod.
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thanks Ray for pointing out this usefull app!
I’m really surprised it doesn’t do this automatically for you. The device could easily check to see if the two values (footpod and GPS) were in alignment. The only times they wouldn’t be is when you’re indoors, or on a treadmill on a boat.
As much as I’m “technical” (I’m a dba) Figuring all that out would probably take me more time than running 800M (which is a PITA) to calibrate the watch. Which just shows how good you are at this stuff! And how bad I am with this stuff!
I was wondering why can’t garmin guesstimate the foodpod calibration using gps automagically.
I just noticed that on the link for the software, under the heading “Supported Garmin Devices,” it appears that only the 310XT is supported.
“This utility works with the 310XT. The 305 and 405 do not seem to record the data required for calibration.”
No mention of the 610, at least not yet.
Very cool but no 305 support
The only issue I see is that it uses a manually entered current calibration. I’ve varied my calibration a couple times from the default, to a self-calibrated, and back to the default with the new FW.
As such I guess I’ll just manually select the run(s) where I knew the calibration factor and see what it turns up with.
Anyone compared this with what Garmin’s self calibration comes up with?
I ran a 800 m on a high school track (2 laps and ending on the exact starting spot) and my calibration values are different from the software that gives me.
Example: 901 (track) vs 991 (software)
Does the pacing done at calibration affect these values?
I could not get it to work with a 210. It says that the tcx file I exported from Garmin connect does not contain footpod data, but garmin connect shows the cadence data.
I wonder how well they do when running stairs.
The lap data confirms what I claimed in the past: the accuracy of the footpod depends on the pace.
Ray, am I correct that the even laps (from lap 4) are fast intervals, while the odd laps (from lap 5) are jog intervals? If so, the accuracy of the footpod differs by about 1% between fast and jog intervals.
The challenge with my rest intervals is that it depends on the workout. Some workouts the rest interval is walking, whereas some workouts the rest interval is Z3 (running). It’s always half the distance of the work interval. For the walking one, usually I’ll walk for the first 1-2 minutes, then jog the rest. Now that I’ve got the tool, it’d be interesting to re-calibrate my footpods and do some interval workouts with it ‘perfectly calibrated’ and see how it does across both my walking (12-15/mile) and my easy running (9-12/mile) compared to my regular running paces (5:30/mile-7:45/mile).
Is there a way for the tool to know what was loaded into the watch in terms of the calibration factor? can this value be determined from the data within the tool? Or do you need to check the watch? Reason that I ask is that I’ve calibrated on several occasions, and I don’t know what was previously loaded in my 310.
Unfortunately not. If you didn’t calibrate, it would be 1,000 by default. But since it sounds like you did, it’d be hard to tell. Sorry!
(I make a habbit of writing down calibration values when I calibrate…just for fun and so when I update firmware when it occasionally erases that value I can just manually add it back in).
Thanks…what a cool tool, just the same!
Hey I just bought the footpod, I was just wondering if there is a way to calibrate it with the Timex Global Trainer?
I know that the data charts that the Trainer makes is different than the garmin series, so how would I adjust the calibration?
Thanks,
Eddie
While the calibration value is ultimately the same (though the decimal I think shifts one place) – the tool only ingests Garmin files, and not the Timex PWX files. Sorry!
I was able to get this program to work today with data from my 305, but I’m not 100% sure if the data is accurate. I had to actually export TCF files from garmin connect in order for the program to read them, but it seems to be working. Here’s a screen cap of some of my 305 data.
link to flickr.com
Ray using garmin fit on my iphone for the first time i hopped the treadmill at my local Y and was amazed at how far off the footpod was according to the treadmill. 3 mile treadmill run was off by round about .5 a mile! yes thats 1/2 mile. I thought maybe the treadmill was off so I stopped and ran on a diferent treadmill another mile and over 1 mile the footpod was long again by 1/10th of a mile. Any clue are the footpods usually that far off or are my local Y’s treadmills likely out of whack? Any suggestions?
what if you have a bunch of files with treadmill runs with the 1000 default calibration? can you go back and enter the calibration to get accurate values from past runs? thanks.
I enjoy your product reviews, they are the best.
Yup, you could. Might be a bit tedious – but the data is there so you could definitely correlate it and go from there.
how would you go about fixing the data? sounds like the 1000 is a multiplier, but of what? or what is the basic equation to use in this instance? thank you.
Thanks for the post, am I getting this right, on the FR60 you would need to run with the footpod and then upload the data and amend the calibration when you know the exact distance?
I have been running with my Edge 305 bike computer in pocket to get GPS distance, so in this case would i do both and then calibrate when uploaded?
Yup, correct to both!
This almost seems like a case of “how to calibrate your sundial with a wristwatch”.
Ya never know when you might have a solar eclipse…
I calibrated my pod using my 910 on an indoor 200 meter track. I used the distance of 800m to set the calibration but I keep getting 863 meters when I’m done, any ideas what could be wrong? The battery in the pod is only a month old. Thanks
Hello! Is it possible to calibrate the footpod without a clock this way? I’ve got a sony ericsson active and a garmin footpood and do not really know how to do a proper calibration. In addition I’ve got an ant+ USB-Stick.
No, ultimately the app/device will need to be able to enter a calibration value – as the calibration is stored in the device, and not in the footpod.
Thank you so much for information! One last question: Do you know if there’s an app that saves both, the gps-track and the footpod-speed, at the same time? I would like to get a gpx- or tcx-file that includes the gps map on the one hand and the speed diagramm from the pod on the other.
Hmm, I’m not aware of any. I’m guessing that probably one of the 150 or so apps that supports the Wahoo Fitness iPhone app does do it, just not aware off hand of any. If you had two devices, you could do it that way, but it’s kinda messy.
Another way would be using two different apps. But then you have to combine two files into one. Is that possible? Anyway, I rather do sports than thinking of all this
You can combine them via Excel or the sort. I do it daily for accuracy tests.