Roth Ira calculation

[arejfour]

I'm self employed person whose income consists of business income, SS, and RMD. I know when calculating my earned income SS and RMD don't count. I've been trying to figure out how much, if any, I can contribute to my Roth IRA. I tried using Form 590A, but, that form is the densest form I've ever tried to use. I gave up after several hours and a headache.  Is there some rule of thumb I can use to try to figure out if I can contribute and, if so, how much?  I've already completed and submitted my taxes for 2021. So, I don't even know if I can make a contribution assuming I'm eligible to even make one. I would appreciate anyone's comments. Thanks

[MinhT1]

Your business income is considered as earned income and would make you eligible for a Roth IRA contribution.

The amount you can contribute if you are not limited by your MAGI is equal to your net business income less the deductible part of your self-employment tax (limited to $6,000 + a catch-up of $1,000 if you are over 50).

[arejfour]

Thank you for your prompt and easy to understand reply. Based on your reply I can, in fact, make a contribution. The question is can I make a contribution for 2021 even though I've already submitted my return and it's been accepted by the IRS? 

[Hal_Al]

Yes, you can still make a Roth IRA contribution, for 2021, even though you have already filed a tax return.  You have until April 18, 2022 to do so.  Be sure to designate, to the IRA custodian, that the contribution is for 2021.  

You do not need to amend your 2021 return, as nothing about Roth contributions is reported, in your case. 

[MinhT1]

Yes, if you contribute to a Roth IRA.

Roth IRA contributions do not need to be reported on your tax return and you do not need to amend your tax return. But make note of the amount contributed and for which year.