How many kilometers (Km) or hours do I walk per day during the trek?

We are trekking in the mountain so we measures hikes in hours rather than kilometers. Normally in the lowlands we hikes 5 to 7 hours per day and it are like 12 to 18 km per day but while we are above 3500 meters than we hike normally 3 to 5 hours per day. It’s all depending on an altitude & condition of the way that we manage the trip.