the wheels on my ford foccus,2003 are 205/50/16s, can i put 245/50/16tires on the rims 205/50/16?

Its probably gonna be too wide and gonna rub

Go here http://www.1010tires.com/TireSizeCalculator.asp
You can input the size of your current tire and the size of the other tires.
It will give you the differences in size down the how much speedometer error there will be.
Look like they probably will be too big.

The stock WHEEL size is 16x6" and the stock TIRE size is 205/50-16. No a 245/60-16 tire will not properly fit on the stock wheels. That size tire requires at least a 7" wide wheel with 8" being optimal. They'll also be almost 1.5" bigger in diameter which will adversely impact the odo and speedometer and you'll quite likely have interference with the fender lip and/or suspension components.