Gradient (Grade %) Calculator

Grade % = rise / run × 100. Convert to angle (degrees) and category (Cat 4-HC).

Inputs

Result

Grade
5.0%
2.86° · UCI category: Cat 1.
  • Rise200 m
  • Run4000 m
  • Grade5.00%
  • Angle2.862°
  • Difficultylength km × grade %²100.0
  • UCI categoryCat 1

Step-by-step

  1. Grade % = rise / run × 100 = 200 / 4000 × 100 = 5.00%.
  2. Angle = arctan(rise/run) = 2.862°.
  3. Difficulty proxy = (run/1000) × grade² = 100.0 → Cat 1.

How to use this calculator

  • Measure rise (m gained) and run (horizontal m).
  • For a known length+grade route, set run = length × cos(angle) ≈ length.
  • Compare difficulty to grand-tour climbs.

About this calculator

A 5% grade means 5 m of rise per 100 m of run — that's arctan(0.05) ≈ 2.86°. Climbs are categorized in road racing by length × steepness² (rough proxy): Cat 4 climbs are 8-20 difficulty units, HC (hors catégorie, "beyond category") are 200+. The Mont Ventoux is HC at ~7.5% × 21 km. Note grade and angle differ — a 100% grade (45° slope) is a black-diamond ski run. Most paved roads stay under 20% even on alpine passes.

Frequently asked

Grade = rise/run (slope). Angle = arctan(grade). For small grades (<10%), they're ~equal; at 100% (45°) they diverge.

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