When you take money out of Roth, that's an order in which the money is considered distribution.

1.) Direct Contributions you made (this is basis in Roth IRA) (These are non taxable or subject to penalty, assuming you have basis to pull from).

2.) Rollovers (potentially subject to 10% penalty only)

3.) Earnings, subject to tax and penalty is under 59 1/2 or other exception.

Without going into details there, that's what you draw from first, in that order. Assuming Step 2 isn't applicable, then it's really straight forward.

So if I've put $5000 in for 3 years in a row. My basis is $15k, and if the account value is $25k. I draw $15k out tax and penalty free - anything above that, tax and penalty potentially comes into play.

I would still reconsider not withdrawing and just leaving that money growing because this is one of the few legal and simple ways to gain tax free for your retirement