Bike climbs can be rated using various methods. This is the method used in the Tour de France. This system takes into account both the length and steepness of a climb as well as its position in the route.
Category 4: Usually less than 2 miles in length. Climbs of 250 to 500 feet in elevation gain. (Norris Canyon)
Category 3: Between 2 and 3 miles in length. Climbs of 500 to 1,500 feet in elevation gain. (Palomares Road)
Category 2: Between 3 and 6 miles in length. Climbs of 1,500 to 3,000 feet in elevation gain. (Mt. Hamilton)
Category 1: Between 6 and 12 miles in length, and steeper than a 5 percent grade. Climbs of 3,000 to 5,000 feet in elevation gain. (Diablo South Gate)
Hors Catégorie (HC) or Uncategorized: Usually more than 12 miles in length, with grades often exceeding 10 percent. Climbs of 5,000+ feet in elevation gain.