Eddington Numbers from your Strava Data

Everyone loves a number to compare themselves with their friends and to gauge your own efforts over time and the Eddington Number is no different. Basically if you’ve ridden 60 miles on 60 occasions, but not 61 miles on 61 occasions, then your Eddington Number would be 60. In order to raise your Eddington Number you’d need to do as many additional rides of 61 miles until you total 61 of them. If this is the first time you’ve heard of the Eddington Number then, like most people, you are currently still scratching your head trying to take that in. But fear not, the Eddington charts on VeloViewer will make it very easy to understand and give you some motivation for some very time-consuming activity!

The details

The Eddington number calculation is based on the distance covered per day (not per ride/activity).  You total up the number of days that you have ridden each distance and plot it out (the blue bars) as shown above and your Eddington Number is the largest distance where you’ve completed it that number of times (where the blue bars intersect with the orange Eddington line).  So for me I’ve covered at least 52 miles on 55 days (but I’ve only done 53 miles on 52 days) so my current, all-time Eddington Number is 52.

Why is it in miles?

The Eddington Number is the brainchild of Sir Arthur Stanley Eddington who spent a lot of coming up with numbers related to Astrophysics. Although I’m sure those were all very interesting, his cycling related number is by far the most important to us right now 🙂

Because Arthur was English, and alive between 1882 and 1944, miles were his unit of choice, and as luck would have it this mile based number provides a really tough challenge for the majority of cyclists.

VeloViewer also provides a km based Eddington as well as time and climbing based numbers.  An important bit of maths often misunderstood is that the km based Eddington number isn’t just 1.6x your mile based Eddington.  If I simply converted my mile Eddington of 52 it would be 88km but I haven’t ridden 88km 88 times, I’ve actually only done it just 48 times.  My km Eddington is actually 76.  More head scratching?

The climbing Eddington is based on metres of ascent but with a multiplier of x20 in order to get the amount of climbing in line with the number of days in a more useful way.

Viewing your Eddington Numbers on VeloViewer

On your VeloViewer Summary page’s Activity Stats section you will see a row called “Eddington”  Here it will show you your mile, km, time and climbing based Eddington Numbers based on the current filters you have selected.  If you pick a single year in the filters then you’ll see the Eddington Numbers for just that years’ activity.

Click the red Eddington button and you’ll get a popup that show the chart shown further up the page.

Improving your Eddington Number

Simply hover you mouse over the different bars in the chart and the tooltip will let you know how many more rides of a particular distance you’d need to complete in order to reach that number.  So if I wanted to get my Eddington Number up to 60, then I’d need to ride at least 60 miles on 25 more days.  That sounds quite doable. OK then, how about getting an Eddington of 100?  Hmmm, looks like I need to do 100+ mile rides on 93 more occasions to achieve this.  Let’s hope I’m still riding once the kids have left home!

Some Eddington based goals

The great thing about these Eddington Numbers is that they offer a great motivation to all types of rider with your W/kg FTP having very little impact on improving your numbers.

Initially you might just try and increase your all-time Eddington Number but with most people having a large part of their cycling history undocumented on Strava the better metric to look at is a yearly Eddington.  Use the year filter at the top of your Summary page to pick last years’ data and use that as a target to beat for this year.

Also take a look at the yearly leaderboards to see how you compare.  You’ll see that in 2016 we had a number of people get a yearly Eddington Number of 100 (they each rode 100 miles on 100 days throughout 2016)!  A couple of riders actually rode 100 miles on 161 occasions during 2016 as part of a century challenge but as they rarely rode over 100 miles each day then their 2016 Eddington Number was 101.  An incredible effort for all that took part though, especially those with jobs to do as well!

0 thoughts on “Eddington Numbers from your Strava Data

  • Jack peterson says:

    Any plans for a similar progress report graph for the yearly Eddington stats, as you say a yearly target is fun and achievable

  • Great post Ben. Just to clarify one point – is it “Total miles ridden in a day” and not individual activities? I believe this is true from my records apart from yesterday (20-Feb). I started the day on 29 and cycled 30.8 miles in 3 activities – commuting. Unfortunately, due to a Garmin operator error, I had to manually log the first 2.7 miles. My Eddington number has not moved from 29 in spite of the day’s riding. Is this intentional?

    • Yep, it is total distance travelled in a day. The calculation is a bit on the simplistic side in that it just uses the activity’s start date for all of its distance rather than splitting it across two days for the odd 24 hour epic ride I’ve seen.
      All because you do a ride of over 30 miles when you have an Eddington of 29 doesn’t necessarily mean your Eddington number will increase to 30. That would require 29 other rides of 30 miles or more. You can ride 365 29 mile rides and one 30 mile ride and your Eddington number will still be 29.
      No plans for any other challenges around Eddington at present.

  • Centenary of Eddington’s eclipse observation that provided confirmation of Einstein’s general theory of relativity is not far away (29 May 2019). Any ideas for a special Eddington Centenary feature / challenge? Eddington’s own E-number was 84 so how about 84 in one year 30/5/18 – 29/5/19 with subsidiary challenge of 84 in 2 years 30/5/17 – 29/5/19? There could also be recognition for “Half Eddingtons” with that special number 42! A Half Eddington over 2 years seems more achievable for mere mortals.

  • Ashley Price says:

    Other than filtering for specific previous years is there a way to calculate your Eddington number at a point of time in the past? This would be very helpful for understanding progress.

  • To echo Ashley’s previous comment, the Eddington numbers are interesting but could be implemented in a more motivating way. A few examples…a progression timeline so that the value at points in the past can be seen. Or notifications when the number changes. Or a mention on the page when new activities are being uploaded/updated in the same way as changes to segment positions are displayed. Or a combination of all of those. Possible?

  • Unless I’ve misunderstood it seems like your Eddington number can never go down, it will either remain constant if you never ride distances longer than your current number, or it will eventually go higher.

    I was wondering if a ‘yearly window’ version could be implemented, as this would keep you on your toes…

    If you started on day 1, then on day 366 the activities on day 1 would be removed. On day 367, day 2 would be removed, and so on …

    • You are correct, your all-time Eddington Numbers will never drop. If you set the year filter at the top of your Summary to just one year then you’ll see the Eddington numbers (and charts) for just that year’s data. If you check out the leaderboards then you can also filter the Eddington leaderboard to display filtered by this and last year.
      If you would like a very hard target then a year or so ago a few people attempted to get a (mile) Eddington of 100 in a single year and I think a couple of people managed it (100x 100 mile rides in a single year).

    • Ben Lowe. Bump. I’d like to get my existing Eddington metrics into a spreadsheet so I can see all my data at a glance. Thanks.

  • So in theory the max. yearly Eddington number is 366 (in a leap year) if you ride every day 366 miles or more?
    I am also curious what’s the record Eddington Number anyone has ever reached. I reached 106 today and need 7 more 107 mile rides to go up one level.

    • I found the answer on swinny.net . The stats on this site claim that the record Eddington Number (among the registered users on Swinny.net) is 192! 3 other users claim Eddington Numbers of 190, 185 and 176.
      After them, there’s a huge gap to 140. Another dozen users are on 130 or above.
      50% of the Swinny-users have reached 47 as Eddington score. 20% has reached level 65 or above. Only 2 percent of the users reached 100 or more.
      62 and 100 show a peak, which means that these distances are a popular ride distance (62 miles equals 100 kms).

  • Really simple feature request: Could yearly eddington increase be added to the infographic?(in addition to “yearly Eddington number”

    Thanks for all the great work

  • Bikelinkin QCW/Cadence says:

    *Not a question, self deprecating observation without letting others who MAY have the question off the hook:

    But why the line and what does the number the line intersects with on the RIGHT Y axis MEAN? (Eventually figures it out … smacks over-thinking self – notes no one else even asked…which means…there’s a lot of people who overthink things as much as me BUT are more shy to unveil their time-to-understanding…or…maybe there aren’t 😉

    • The line is just x=y, i.e. the number of activities/days you need to reach a specific Eddington number. Where it intersects on the right is fairly arbitrary and will depend on your own data and the y value will always just be the max x value on the axis. The scales change based on the riders activity counts and current Eddington to hopefully clearly show where they currently are and what they need to do to improve their Eddington.
      The idea for the line is to show how many activities/days you’d need to reach a specific Eddington value.

  • marco zimmerman says:

    hi, I wonder if my eddington number includes all activities in my strava (for example rides with my racebike and my ebike) or only 1 type of activities ?
    Please respond if you know this.
    Best regards,

    • Hi Marco. On the Summary page the Eddington numbers will be using all of the data you currently are showing. If you filter by Ride then it’ll be just for that type of activity. No filters and it will use all of your sync’ed data.

  • How does calculation work with activities started before, but ended after midnight. Does this count as 1 one day taking the full distance, or is there some smart splitting going on at the background?

    eg. I ride 100k: 50k before midnight, and 50k after midnight. Does this add as 1 time 100k, or 2 times 50k?

    • Hi Victor. For the Eddington it just uses the start date and puts all the distance into that. I did put out a question to the community around this way back when I wrote the code and it seemed to be the accepted method. You can always split your activities at midnight if you specifically want to put the distance into each day.

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