Easy
Usual daily walks of 4 - 5 hours in altitude below 4000 meters. The sleeping altitude on these treks are below 4000 meter and the trails are gradual involving no steep ascent or descent. Sometimes, the trail may be longer, but on level trails. The duration of trek may be a week or lesser than it. The trek is not too remote and evacuation might be possible from almost any point of the trek
Moderate
The trek duration each day may span from 4 - 5 hours, but on some days, it may push up to 8 - 9 days. The trail might involve steep ascents or descents on occasions This kind of treks demand good fitness, and trekkers must involve themselves in cardio exercises regularly to do these treks comfortably. Sleeping altitude are below 4000 meters or little above it, but the trail might go as high as 4500 - 5000 meters. The trek is bit remote and evacuation might be possible from almost all, but not all campsites
Moderate +
This type of treks are bit more demanding than the moderate ones. It might involve few days of very long walks at higher altitude, or serious gradients, exposures, more remote or involves sleeping at higher altitudes for more days.
Strenuous
The trek duration each day may span from 5 - 8 hours, and may go up to to 8 - 9 on few days. The trail involves steep ascents and descents. Good fitness are demand of these treks, and trekkers must involve themselves in cardio exercises regularly to do these treks comfortably. Sleeping altitude may go above 4000 meters or little above it on couple of days, but not more than that. The trail might go as high as 4500 - 5200 meters. These trek are remote and evacuation might not be possible from all the campsites
Challenging
The trek duration each day may span from 5 - 8 hours, and may go up to to 8 - 9 or even more than that on few days. The trail involves steep ascents and descents. Crossing a glacier or a scree zone might be a feature of these treks. You might on some occasions, require technical equipment like rope, ice axe and snow stacks etc to complete these treks. Good fitness are demand of any treks, but these treks demands strong character. Sleeping altitude may goes well above 5000 meters on some days. The trail might go as high as 5000 - 6000 meters. These trek are high or remote or both. The trek usually might be a week long.
Sometimes irrespective of altitude and distance, a trek may ge graded Challenging if the route is treacherous, which might demand some footing skills or assistance of ropes and other equipment
Challenging +
The trek duration each day may span from 5 - 8 hours, and may go up to to 8 - 9 or even more than that on few days. The trail involves steep ascents and descents. Negotiating glacial moraines, scree zones, crossing them, camping on them etc are features of these treks. You might also require technical equipment like rope, ice axe and snow stacks etc to complete these treks. Good fitness are demand of any treks, but these treks demands strong character. Sleeping altitude may goes well above 5000 meters on some days. The trail might go as high as 5000 - 6000 meters. These trek are high and remote. A good technical support team and knowledgeable local guide is a must. Only experienced trekkers are advised to do these treks. The trek goes over 2 week and may be longer than that.
Sometimes irrespective of altitude and distance, a trek may ge graded Challenging if the route is treacherous, which might demand some footing skills or assistance of ropes and other equipment