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 or MapMyRide route?

In this post, I aim to find out.

But first a bit of history.

## 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 do Strava and MapMyRide classify climbs?

Both apps use 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 and MapMyRide 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

Strava is the most specific about how it goes about calculating 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.

### MapMyRide

MapMyRide is less explicit in how it calculates the classification of a climb.

In addition to the length of the climb and its average gradient, MMR’s calculation also takes into account “maximum elevation”, although it’s not clear whether this latter variable refers to height gained (students of Pythagorus can debate whether this is necessary) or final altitude (and could thus factor in the difficulty of performing in thinner air).

Like Strava, MMR has minimum criteria for a climb to be classified. The climb must be at least 500m long and have an average gradient of 3% or more. This is significantly lower than Strava, where a 3% climb would need to be 2.67km in length to be classified (8,000/3). This is because…

MapMyRide has one more (easier) climb category than the Strava/pro-cycling model. This category 5 classification alone is probably sufficient to blot MMR’s copybook as far as most deluded pro-tour wannabes are concerned (note: I count myself amongst that number), as is their statement that, “[MMR's] methodology is unique in several ways to allow for categorizations to be relevant for all sports…”. In other words, if you’re a cycling purist, you’ll probably prefer Strava.

Although the specifics of what leads to a category 1 to 5 classification are not disclosed, MapMyRide does reveal that an HC climb will normally have at least two of the following characteristics:

- Longer than 10 miles
- 8 – 10%+ average gradient
- “very high (above 11,000 feet)” (Quoted directly, because I’m not sure exactly what they mean)

## The Grimpeur’s Choice

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 looked at their respective climb classification methods, 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.

I would love to hear your experiences with Strava and MapMyRide. Which is the hardest category climb you’ve found near you (the ones nearest me all seem to be 3s and 4s)? Let me know in the comments below.

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{ 6 comments… add one }

[...] How do Strava and MapMyRide Determine Cycling Climb Categories? [...]

New post on my blog: how mountain climbs are classified on #strava and #mapmyride. It’s good – honest! http://t.co/ZATXm4Fa3R please RT!

@racepaceblog Hi Phil – wondered if my latest post is of interest to your clan http://t.co/ZATXm4Fa3R – re: strava climb classifications

@chestnut38 @HammondMat @velopixie @YeeAlan Strava chaps – latest post is about Strava: http://t.co/DJpAy98jms

All sounds good but in reality I am not very convinced by the system. Looking at my recent King of the Downs ride:

http://app.strava.com/activities/57699006

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.

Great blog by @GrimpeurHeureux detailing how Strava climb classifications rate vs. pro-| http://t.co/z3B0TJ6oUM

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.

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 http://www.mapmyride.com/ie/swords-l/103-83-kilometer-bike-ride-on-feb-4-2012-route-67552364 . It is shown as having 5 categorised climbs. Have I misunderstood something here?

Doug

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…

[…] You’ll enjoy the other posts in my Strava vs MapMyRide series: How do Strava and MapMyRide Determine Cycling Climb Categories? and How Does Strava Calculate Power […]

All sounds good but in reality I am not very convinced by the system. Looking at my recent King of the Downs ride:

http://app.strava.com/activities/57699006

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.

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.

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 http://www.mapmyride.com/ie/swords-l/103-83-kilometer-bike-ride-on-feb-4-2012-route-67552364 . It is shown as having 5 categorised climbs. Have I misunderstood something here?

Doug

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…