Look at the manual on how to check the oil properly, alot of guys do not do it correct. Some engines you have to run it for a minute and then wait a minute before you check the oil level.
If you follow the procedure in the manual when removing the old oil, you will get use 1 gallon to replace it. This will bring it up to the mid-range on the dipstick. That's why the oil change kit comes with a gallon of oil.