Grade A: Easy to Medium
Easy trekking by Himalayan standards is usually up to 2000m. There are many ups and downs on well-maintained trails. This sort of trip is the best suited for those that lead a quite active life. The trek takes about 3 to 7 days, walking about 4 to five hours each day.
Grade B: Medium to Hard
It involves longer treks (five to 10 days) on maintained trails. This type of trek includes day excursions to higher elevations, so it's advisable to possess some previous hill-walking experience. We generally achieve an altitude between 900m to 3000m in medium to hard treks.
Grade C: Moderate To Strenuous
These treks must be fully supported. We climb to altitudes between 3500 and 5000m. There are overnight stays at an altitude above 4000m. For this trek, trekkers must be fit, enthusiastic hill walkers to tackle rough terrain in remote areas.
Grade D: Very Strenuous
We describe this trek as an Alpine suitable for those in excellent health and capable of carrying a backpack when required. The trek covers most of the remote areas, traveling over snow-covered passes at an altitude of up to 6500m. You will get to axes and crampons. You are not allowed to perform strenuous treks without medical clearance.