How Does Strava Determine Cycling Climb Categories?

As an avid pro-cycling fan, and particularly of the Grand Tours, I have always been fascinated by the classifications given to the climbs along the route.

The sight of one or more Hors Catégorie climbs on the route profile for the following day’s stage means that I’ll have to clear my schedule for an afternoon spent glued to the television.

But how do the climb classifications seen in the Tour de France or the Giro correspond to those that appear on our recently completed Strava route?

In this post, I aim to find out.

But first a bit of history.

How Strava Classifies Climbs: In Video Format

Why Do We Have Climb Classifications?

The concept of categorising climbs within the Tour de France was introduced to make the mountain points system more reflective of the relative difficulty of each ascent.

From 1933 (when the mountains jersey was introduced) until 1947, riders were given the same number of points (10 for first over, down to 1 for the tenth-placed rider), irrespective of how high or how steep the climb.

From 1947, climbs started to be graded by difficulty (with two categories initially, increasing to the present day five) and the awarding of points was adjusted accordingly (i.e. fewer points awarded to those riders first cresting the easier climbs).

How Do Climb Classifications Work In General?

As mentioned, the Tour de France features five categories of climb, ranging from hors catégorie (HC), the most difficult, then 1, 2, 3 and 4 (the easiest).

Hors catégorie translates to ‘beyond categorisation’. It’s the catch-all classification for anything that is harder than a category 1. Historically it was used to describe a col that cars would not be able to climb. Given the number of skier-filled coaches that get up Alpe D’Huez (used 23 times as an HC climb in the Tour), that distinction no longer applies.

Broadly speaking, the longer the climb and the steeper the gradient, the more difficult the climb is deemed to be, and it is graded accordingly. Overlaying this, when a climb features in a cycling race, the organisers look at where it comes in the route and potentially adjusts the classification. What might be a category 1 climb as the first col of the day, could become HC if it is set as the mountain top finish of a grueling Alpine stage.

So How Does Strava Classify Climbs?

Strava uses a methodology similar to professional bike racing, employing a formula based on a climb’s length and its gradient.

A key distinction versus the Tour de France approach is that climbs on Strava are classified on an individual basis, using terrain data. Classification is not influenced by where a climb features on a cyclist’s route. A cat 4 is a cat 4 whether you ride it straight out of the gate or at the end of a long hard day in the saddle.

Strava is open and specific about how it calculates a climb’s category. The length of the climb, measured in metres, is multiplied by its gradient, in per cent (for maths pedants, they use the ‘whole number’ per cent rather than the decimal, so 10% is 10 rather than 0.1).

In order to be categorised at all, a climb must:

  • have a gradient of at least 3%; and
  • achieve a score of 8,000 or higher (so 1km at 8%; 1.5km at 6%; 2km at 4% etc).

If the minimum criteria are met, climbs are classified according to the following points scale:

  • 8,000 or greater: Category 4
  • 16,000 or greater: Category 3
  • 32,000 or greater: Category 2
  • 64,000 or greater: Category 1
  • 80,000 or greater: Hors Catégorie

Again, for maths purists, the Strava site is a bit imprecise as to whether each threshold is a ‘greater than’ or a ‘greater than or equal to’ but I doubt it really matters (you’ve got to imagine there is a far greater margin of error on the terrain data used for the calculations).

A Strava segment (a user-defined route section over which Strava users compete for the fastest time) is automatically given a classification if it meets the required climb criteria. If you are riding a route without defined segments, Strava will automatically determine if you cycled up a classified climb and create a segment for it.

Which Is The Best App For Cycling Climb Classification?

If you’ve already read my comparison of Strava and MapMyRide, you’ll know that I am already a huge fan of Strava.

(If you haven’t read it, you should).

Having compared Strava’s climb classification methods with alternative apps (MapMyRide for instance), my preference for Strava seems increasingly justified.

The calculation is clearer (i.e. they say what their methodology is) and it is not sullied by whatever adaptations MapMyRide make for the benefit of walkers and runners. That said, I’m sure an HC on MapMyRide is just as painful as one on Strava.

Other Strava-related Posts (In Case You’re a Strava-phile)

Monty - Sportive Cyclist
Monty is an enthusiastic road cyclist with only moderate talent. He started Sportive Cyclist in 2013 to record the journey to his first 100 mile ride, the RideLondon 100. Over time the blog has expanded to include training advice, gear reviews and road cycling tales, all from the perspective of a not-very-fit MAMIL. Since you're here, Monty would also like you to check out his YouTube channel. Also, Monty really needs to stop referring to himself in the third person.

22 thoughts on “How Does Strava Determine Cycling Climb Categories?”

  1. All sounds good but in reality I am not very convinced by the system. Looking at my recent King of the Downs ride:
    It gives everything a category of 4 apart from Box Hill which was by far the easiest climb out of the 5! Leith Hill (which I found pretty tough) is only a 4!
    I was really surprised how easy Box Hill was. It’s a while since I’ve done it (last year) and I remember how hard it was the first time I did it. Barely noticed it was a hill at all this time!

    • I’m afraid to say it Giles, but it probably reflects the fact that climbs in the south east of England (as well as much of the rest of the UK) are just not as long or go as high as those on the continent.

  2. The Strava point total is necessarily equal to the elevation gain in meters multiplied by 100, which I believe is a less convoluted means of describing the calculation. (The multiplication by 100 is due to using for instance 10, rather than 0.1 to represent 10%. The grade, 0.1 here, when multiplied by length of the climb in meters is the elevation gain in meters. But since we use 10 and not 0.1 we get 100 times the elevation gain in meters as the point total.)

    Thus, it is very easy to calculate category on the fly. For instance, if we know a climb is 300 meters, we take 300 times 100 = 30,000 points, which is category 3 (approaching category 2). The only additional stipulation is that the average grade is at least 3%. (This eliminates scenarios like a 20km climb at 2% average, which otherwise would qualify as a category 2.)

    • Thanks SP. That’s right. I guess it’s helpful to have in mind both versions of the calculation:

      If you see a sign that says 9.5km at 7% (like this one), then (if you’re compos mentis) you can work out that the Strava points score is 66,500 (and therefore a Cat 1).

      Alternatively, if you know the height is 668m then, as you say, multiply it by 100 (and confirm that the average gradient is greater than 3%) and you’re at pretty much the same points score.

    • Yes, if gradient formula is elevation difference divided by distance to ride, it is nonsense to multiply the gradient by distance, distances cancel themselves.
      So distance to ride is not a function of climbing category.

  3. Hi, I’m confused about the criteria for a climb to be rated on Map My Ride. The MMR website says for a climb to be categorised it must have an average gradient of 3% or greater and be at least 500m long. However, the 3% rule does not seem to be applied – see for example the route at this link where none of the climbs have a gradient of 3% or greater . It is shown as having 5 categorised climbs. Have I misunderstood something here?

  4. Hi Doug – you’re right (or rather, I share your understanding of how MMR classifies its climbs). In fact, in that ride you linked to, climb 2 seems tougher than 1, yet is rated 5 (when climb 1 is rated 4). Climb 2 seems to stop once you’ve already started to descend – the high point seems higher than the 120m figure shown. Very strange. I’m afraid I don’t have an explanation…

  5. This post is quite a bit after the fact, but I did a ride today that ascended 755 feet in .9 miles. The data was logged with Map My Ride. So first, I am over the 500m threshold. That’s a 15.8% grade (this was a mountain bike trail in Colorado). Map My Ride didn’t qualify it as a hill climb at all. According to MMR “For any climb to be rated (receive a climb score/category) it must be at least 500 meters in length with an average grade of 3% or more.” They also account for final elevation – I wound up at 7100 feet. MMR continues ” All other climbs that do not meet the criteria for HC to Cat 5 are simply too small to rate and can usually be crossed easily by bicycle, running, or walking.” I would by no means consider my ride easy. Before that .9 mile stretch I had already ascended 500 feet in 1.2 miles. Yes it was very short, but it was brutally uphill – AND it qualified for MMR by being over 500m in length. So what gives?

    • Hi Jim – thanks for the comment. I’m afraid that despite their explanations, it’s still a bit of a black box…

  6. When I started using Strava, the programme did not record all the routes etc and I also had problems with the thing closing down before finishing my ride. No matter how many times I queried the problems with Strava they were quite unhelpful – so I switched to Map my Ride and whilst I had a few issues, all these were answered with simple explanations and have been on that system ever since and it’s the Free version. I am sure “each to their own” but I am quite happy with my MMR.

    • I also prefer MMR. It is more user-friendly for This user! I did like Strava’s Beacon Text, but now that I use Life360, I don’t really need it. Personal preferences vary quite a bit. If a product, or app doesn’t deliver what you need, it isn’t really superior, it’s just another option.

      • I second that … I tried Strava for a day but quickly dumped it, I find MMR much, much, much easier to use. Better overviews, less clutter with functions I don’t use, quicker to do what you need.

  7. That’s all well and good, but as a MapMyRide user I’ve tried out Strava after reading your article and I was seriously disappointed by its UI and usability.

    Both the app itself and the accompanying website for MapMyRide are IMO *way* easier to use and provide a better and more clear overview of my workouts/activities … with Strava I spend more time clicking around, getting confused, and still not getting what I’m looking for than with MapMyRide.

    Strava’s UI is full of features that I’m not interesting in using but which take front stage over the ones that I do want to use.

    I’m not commenting on the accuracy, but I suggest that Strava’s UI/UX designer takes a class from MapMyRide’s designer.

    And by the way, Strava identified my “small” climb at the beginning of my ride (without showing any climb classification …) but ignored the much bigger and steeper one at the end … weird.

    For some unknown reason MapMyRide sometimes identifies the (complete) climb and sometimes doesn’t, on the same route, but at least this time it got it more or less right (only it included a virtually flat stretch at the beginning, which made the whole climb look much less steep than it actually is).

  8. This metric is equivalent to total meters gained, which obviously is not the best way to measure a climb. A 10% climb rising 100 meters is obviously going to be harder than a 5% climb rising 100 meters!

  9. Hi there,

    Searching around on Google, I can find nowhere a clear method to determine the start and the end points of a climb. I get the avg gradient calculation and the categorization/classification of a climb, but how do we first identify the climbs themselves. 2km of 2% may not be a climb on itself, but what if it is followed by 10km at 7% ? is the first 2km then part of the climb ? When is there enough descent or flat between uphill sections for one climb to become two climbs ? Is there any generally accepted methods to determine starting point and end point of a climb ? Thanks for your help,

  10. Hardknott Pass, the hardest hill in England, 3rd hardest in the world is only a Cat 2…
    I can’t understand as Alpe D Heuz is a walk in the park comapred to that.


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