Occupancy in a hotel is calculated by the number of occupied rooms divided by the number of available rooms that physically exist in a hotel. For example, if Occupancy is 65%, this means that 65 rooms are occupied if the hotel has a total of 100 x rooms.
The occupancy forecast is a written/reported estimate of the number of rooms which will be sold/occupied on an identified day and/or for a specified period of time. Examples would be a daily occupancy forecast, a monthly occupancy forecast, quarterly, and even a full annual occupancy forecast. In other words, the occupancy percentage that the hotel predicts will eventuate.