How are climbs categorised?

Climbs are rated from Category 4 (easiest) through Category 1 to Hors Catégorie (HC, beyond category). The rating considers both length and steepness.

What makes a climb Hors Catégorie?

HC climbs are typically long and steep — generally over 15 km at 7%+ average gradient, or shorter but extremely steep (e.g. 10 km at 10%+).

How does the scoring work?

The difficulty score = length (km) x gradient² (%). This weights steepness more heavily than length, reflecting the physiological reality that steeper climbs are disproportionately harder.

Are these categories the same as the Tour de France?

These are approximate. Real race categorisations also consider the position in the race, road surface and other factors. This gives a good general classification.

BikeCalcs

Climbing Category Calculator — Classify Your Climb

Classify a climb by its category based on length and gradient.

Climb Length

Average Gradient

How We Calculate This

Climb Classification

Score = Length (km) x Average Gradient (%)²
Cat 4: Score < 80
Cat 3: Score 80-199
Cat 2: Score 200-399
Cat 1: Score 400-799
HC: Score 800+

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify results and consult a professional bike fitter where appropriate.