1099-R only reports withdrawals. Contributions are reported on form 5498. You need to know the total of your contributions from your own accurate records. If you list Roth contributions in TurboTax, the program is supposed to help you keep track, but it doesn’t get reported on your tax return unless you are a low income and qualify for the retirement savers credit. But that still doesn’t track your whole total contributions.
You would only need to know your contributions if you make withdrawals before age 59-1/2. If you wait until after, all your withdrawals are tax free no matter if they are earnings or contributions.
