Very Easy: treks less than 30 minutes in paved/cemented roads or clear paths
Easy: Single trail lasting less than 2 hours in length, not exceeding class 2
Mild: Trail requiring less than 2 hours but with parts exceeding class 3; or 2-5 hours in length but not exceeding class 2
Average: Trail requiring 2-5 hours, with parts of trail class 3 or higher; or trek lasting 5-9 hours, with parts of trail not exceeding class 2
Moderate: Trail lasting 5-9 hours with parts of trail class 3 or higher; or all long treks not exceeding class 2
Challenging: Mountains under class 5 with place-specific circumstances not accounted for by trail class
Difficult: Trek lasting 5-9 hours, with parts of trail class 4 or higher with cold weather OR trek requiring 3 or more days
Strenuous: treks requiring more than 3 days average with varied, potentially hazardous environments or Trail class 5-6 for 2 hours
Technical: Either Trail class 5-6 more than 8 hours or very long treks requiring 4 days average or less than 3 days but exploratory in nature and summitability non-assured