There are variations in the level of difficulty and altitude in Nepal. Based on the region and trips, trip grades can be divided into five different categories. Basically, it applies to trekking, peak climbing, and expeditions.
Easy or Grade A (*)
Easy grade means you do not find any difficulties to trek. The trip reaches up to 3000 meters in altitude. The trails will not be rugged, and these types of treks are highly suitable for family trips. The trips are generally around 1 week.
Moderate or Grade B (**)
Moderate or Grade B trips include a 1- to 15-day itinerary. It can reach up to 5000 meters in altitude, but the trails will be moderate (neither easy nor tough). High altitude may affect walking speed and distance. You need to have acclimatized over 3000 meters.
Strenuous or Grade C (***)
Strenuous trekking is both moderate and difficult. Even in this grade, treks reach around 5000–5500 meters. You walk generally 6-7 hours every day. Strenuous treks require good physical condition and acclimatization. If some problems appear, you have to walk down and take some hot drinks or soup. You may get affected quickly if you have high blood pressure, asthma, heart disease, or other complicated medical conditions.
Very Strenuous or Grade D (****)
Very strenuous trekking covers 4000 meters to 6000 meters. No doubt, your physical fitness and acclimatization are essential. It is said that generally you walk about 7 hrs every day, but the altitude becomes obstacle and it is really tough to walk that much. You have to cross the Himalayan passes using basic climbing equipments. Even the trail is steep and slippery.
Technical Challenging or Grade E (*****)
Technical Challenging Trekking grade is for those who really love to do extremely adventurous treks/trips. Its elevation reaches up to 6000 meters and consist 15-25 days itinerary. It is not less than peak climbing.