That's a great question! The average height of a Christmas tree can vary depending on the species of tree and where it's grown. The most popular Christmas tree species, like the Douglas fir and the Norway spruce, typically grow to heights between 40 to 60 feet tall. However, the average Christmas tree that you'd find at a lot or in a store is usually between 6 and 10 feet tall. So, it really depends on the type of tree and where it's grown.