How many credit cards is good for good credit?

I currently have 3 credit cards. A capital one, gap and just opened a citi bank a month and a half ago. I currently have a score at 684 and have had my capital one open for 2 years now. I am 21 but I want to make my score higher. I pay the cards off in full all the time but is one more card too many? will that affect my score if I have 4 or 5 cards?

It isn’t so much how many credit cards you have, but how you manage them – along with how you manage the rest of your finances. Make sure you pay your bills on time (phone, hydro, etc.) and in full. Check your credit profile on occasion to make sure there are no mistakes or forgotten bills from the past. It takes time to build up a good score.