It depends on what accord you are talking about...coupe or 4 door?
the coupe lx I have had 15 inch rims with 195/65 tires. the total width of the tires was about 25 inches. If you put bigger rims you will most likely want to put low profile tires on them. If you go with 17 inch wheels and put 205/40 tires you will actually get a smaller diameter than the stocks...something like 23.5. So you loose an 1.5 inches by going bigger because of the tires. If you want to go 17 you will have to put 205/50s to just match the stocks. If you find these tires they will most likely cost A LOT. In comparison, if you go 18's and 225/40 tires, the diameter will be 25.1 The coupe's wheel-well are huge...I think mine (2001) were 29 something accross so when I put 17's on it they looked tiny. The 4 door is probably smaller so you may be ok. I bought 17s and 2 weeks later I went back to put 18s on and drop the car 1 inch. If you are going for a sporty look, look into 18s or 17 plus a small drop that will not require a camber kit.
spend some time in www.cardomain.com and sort the rides for honda accords from 98 to 2002 or your specific year....90something percent if not more will have 18s on.
go to the toyo tires website to see what diameters you will get with a speicific tire. Remember that how "big" the overall wheel will be depends mostly on the tire so if you are concerned about the "gap" between the tire and the wheel-well edge be carefull about putting 17s on because it will actually increase. if you put /40 tires on.