Understanding solo 401k limits in context of profit sharing and backdoor roth

[spiritrider]

Yes

[Chessknt]

The maximum self-employed employer contribution is 20% of your net earnings from self-employment (earned income) = business profit - 1/2 SE tax.

Each unaffiliated employer has a separate annual addition limit (2021 = $58K).

The 401k and IRA contribution limits are separate.

Thanks for the response. So my IC gig 58k contribution is separate from the profit share at my w2 job?

[spiritrider]

The maximum self-employed employer contribution is 20% of your net earnings from self-employment (earned income) = business profit - 1/2 SE tax.

Each unaffiliated employer has a separate annual addition limit (2021 = $58K).

The 401k and IRA contribution limits are separate.

[Chessknt]

I am currently a W2 employee with no 401k but part of a profit share that will give me somewhere between 10-40k per year.

I am also a 1099 with a different group from my primary employer and will make around 80k/yr with this group.

I also want to max out my roth IRA via backdoor method.

If I put 1099 earnings in to a solo 401k I assume I am allowed to do 19.5k (employee contribution) + 20000 (25% of 80k)--does this reduce my allowed contribution to a traditional IRA (that I then convert to roth)? Does this overlap with my unrelated profit share that might put me over my annual 401k limit? I won't find out the profit share amount until Feb next year and can wait to do my 1099 contributions until after that if they interfere with each other but it is a bit unclear if these are unrelated enterprises if they have the same limit applied.