Easy trekking (Grade One)
If you do not have any experience for trekking, you shouldn’t be worried about it. The easy treks are design for everyone or in another meaning you can say it is for beginners. Old people, children & family can enjoy these types of trekking. You need to walk up to 6 hours every day in the mountain area & you can take rest while walking. Most of easy trek will be below 4000 meters of altitude and there will be rare chance of acute mountain sickness. Average fitness level persons can do this trip easily.
Ghorepani Poon Hill, Everest short trek, Around Kathmandu valley trekking, Royal & Panchase trek is great example of easy trekking in Nepal.
Moderate trekking (Grade Two)
Moderate trekking might be a bit challenge for first time trekkers but if you are physically fit and doing exercise regularly, you can do grade two level treks. The average altitude of these treks will be 3900 meters to 4800 meters. Generally walking in these trips will be up and down and sometimes slightly higher passes from where you can enjoy close view of the Himalayas. It might be tough for old people (65 +) & children.
Annapurna base camp, Langtang valley trek & Gokyo lake Everest trek are moderate level trekking.
Strenuous trekking (Grade Three)
Physically fit, stamina and good health condition required for strenuous trekking. These treks are adventure trekking where you need to cross the passes, walking more than 7 hours (not for all days, but few days it requires) and generally the altitude will be above 4800 meters to 5600 meters. We will get a chance of real encounter with Himalayan people in these treks. Stunning Himalayas in front of your eyes will motivate you to enjoy the trekking days. Your accommodation will be at Tea House Lodge and you should not expect modern facilities like in cities in trekking days.
Everest base camp, Annapurna circuit, Upper Mustang trek, Guerrilla Trail will be your best choice for strenuous trekking in Nepal.
Note: Accommodation will not be good enough in Guerrilla trail as comparison to other regular trekking trails.
Challenging/Alpine trekking (Grade Four)
The tough treks in Nepal which are adventure holiday trips. Challenging treks will be high altitude trips and you need the cross high passes, snow filled lands and sometime Himalayan Mentor’s trekking crews helps you to make the path as well. The high level of stamina and previous trekking experience helps you to trek in alpine trekking trails. Few treks can be done in camping style and few are possible with Tea House /Lodge basis. Trip duration for these trips will be more than 20 days.
The most popular challenging treks in Nepal are Upper Dolpo trek, Everest high passes trek, Ganja La pass trek, Manaslu trekking, Kanchenjunga trekking etc.