How Tour de France Climbs Are Categorised: Why Some Mountains Are Harder Than Others
When the Tour de France reaches the mountains, each climb is stamped with a category — Category 4, 3, 2, 1, or the fabled Hors Catégorie ("beyond categorisation"). The label decides how many points the mountains classification awards, and it gives viewers a quick sense of whether a climb is a gentle bump or a day-defining ascent. The system is borrowed from the way French road engineers originally graded mountain roads for maintenance, then adapted for racing.
The categories, from gentle to brutal
The Tour uses five bands. Lower numbers mean harder climbs; Hors Catégorie (HC) is the highest difficulty. The ranges below are guidelines, not hard thresholds — the race jury sets the final rating and adjusts for context.
| Category | Typical length | Typical average gradient | Points for first rider |
|---|---|---|---|
| 4 | 1-2 km | 3-5% | 1 |
| 3 | 2-3 km | 5-7% | 2 |
| 2 | 3-5 km | 6-8% | 5 |
| 1 | 5+ km | 8%+ | 10 |
| Hors Catégorie | 10+ km | 8%+ (often sustained) | 20 |
The point totals feed the polka-dot jersey competition. A single HC summit can swing the classification more than four Category 4 climbs combined, which is why breakaway specialists target the bigger mountains even when a stage win looks unlikely.
How the race jury actually assigns a rating
Tour organiser ASO follows a rough formula that combines length, average gradient, and maximum gradient, then applies judgement. A short, steep ramp of two kilometres at 12% might rate as Category 2 rather than 3 because of its punishing pitch; a long drag of fifteen kilometres at 5% might rate as Category 1 rather than 2 because of its cumulative fatigue. Altitude matters too: a climb finishing above two thousand metres is treated harder than its raw gradient suggests, because the final kilometres arrive with thin air and a long day already in the legs.
The jury also weighs where the climb sits in the stage. A Category 2 used as the final summit finish carries the same rating it would as a mid-stage obstacle, but it shapes the race more. That placement does not change the category; it changes only how the peloton rides it.
Why the same climb can be rated differently
Climbs are not intrinsically categorised — they are rated for a specific edition of a specific race. Several factors flip the rating:
- Start elevation. A climb begun from a valley town gets its full length counted. If the stage crests a preceding hill and rolls into the base, riders arrive already fatigued and the jury may rate the following ascent harder to reflect the real difficulty.
- Finish placement. Alpe d'Huez, the Col du Galibier, and the Col du Tourmalet have appeared as HC climbs when used as summit finishes and as Category 1 climbs when positioned as a mid-stage passage that the riders still have to descend.
- Partial ascent. Races sometimes climb only the lower section of a mountain rather than the whole road to the pass. The same name can therefore appear as a Category 3 in one year and an HC in another.
- Different race, different jury. The Giro d'Italia and Vuelta a España use the same naming scheme but apply their own thresholds. A climb listed as HC at the Vuelta can appear as Category 1 in the Tour, because each organiser calibrates to the mountains on its own route.
Why categorisation matters beyond the polka-dot jersey
Category ratings shape stage design as much as rider reward. A stage featuring two Category 1 climbs and an HC finish is built to separate the general classification contenders from the breakaway riders. A stage with four Category 4 climbs invites an early escape and a flat finish. Television schedules, team tactics, and even how much food riders carry in their pockets are informed by the dotted category labels on the route profile.
The system's quirks are part of its charm. Ratings are a judgement call, not a measurement, which is why fans argue every July about whether a given climb was mispriced — and why a route designer's choice to upgrade a familiar mountain can be a story in itself.
Categorisation is best understood as a shorthand: a category tells you roughly how much a climb will hurt, not exactly how it will be raced. That gap between label and reality is where the Tour's mountain stages earn their drama.