So you take a 48 square meter room (taking into account wall height) and add to that 18 sq. meters of celing space...you get 66 sq. meters. SO, if one where to buy 100 sq. meters worth of paint...one should have enough to finish the job and have some left over, right? Wrong! Apparently the rough plaster sucks a lot of paint...even though I told the paint person at the hardware store that I had roughly plastered walls...