Guys, don't look at the what to mine website for calculations, it's too way off.
Better use your brain and make calculations by yourself, it's more accurate than wtm.
Its not off if you don't use the current difficulty option. The problem with many of these coins is they fluctuate difficulty significantly through out even a 24 hour period so if you use just the current difficulty as a guide then you may be sadly mistaken.
Use the 24h average difficulty or higher to see what your more realistic returns are going to be. You can't expect to know what is going to be most profitable in 24 hours or longer if you can't predict what the difficulty or price of the coin is going to do in that time.