I have a 500 chip set and ive played with 7 people and we didnt even unwrap all the chips so its definitely enough, plus when people get knocked out everyone gets more chips anyway. Just open up all the chips and deal them round to everyone until you all have the same amount of colours, you may need to put a few back into the case if it doesnt deal out evenly.
With 7 people i would recommend using the whole set, that way everyones playing for longer, nothing worse than going out straight away and having to wait hours for everyone to finish.

Oh and remember, never trust the player who tries to buy the pot. Happy gaming

500 chips is small. Is it enough, I don’t think so. My friends and I have a game at least once a month and the chips we require are in the neiboughood of 3000.
If you can afford more chips, I would recommend buying more. This will help if people need to buy-in again, creating change, etc.

If you have only these chips, and at least 4 colors of 125 chips each, I would recommend this format:
Color A - 10
Color B - 25
Color C - 50
Color D - 100
Then each player will have 1000 to start with 10A, 10B, 7C, and 3D.

Ya, it should be plunty. But really depends on how you play. Some people make all the chips equal or they make them different value. But either way I think it should be plunty.

If you play all chips equal, which I don’t prefer. You should probably give everyone 100 chips or so.

If you play different value, make the chips value equal to about 500 or so.

using standard guides u probably have enuff for 20 players. look online there are guides everywhere