Not sure as the tiles are an odd size (approx. 20" X 20"). My trailer is a 20 foot. I bought 50 tiles for $125 on Ebay with free shipping and a 3 1/2 gallon bucket of glue from HD. Had 7 or 8 tiles left over and I screwed up a few cuts and had a couple of stained tiles that I threw away. I would guesstimate that 50 tiles would do a 25 foot trailer easily. I still have to caulk between the tiles to be completely done but I am very happy with it. I will keep everyone posted as to wether they stay up after traveling. Hoping to take a test run next weekend. Heres one more pic from today.

Very Nice!
 

I think that it looks awesome! Congratulations.

I did not vote on the tile you selected, but it looks great!!