Total Tax Due Estimating, how can I do it?

[Heroes821]

So I'm trying to understand how my entire tax burden works as a single employee S-corp and I feel like I understand the FICA portion, my personal Income tax and the State Income Tax. Unemployment taxes (state and federal) still confuse me, but I was hoping to find a spreadsheet or IRA fillable form or something that would let me punch in a best income scenario, like I make X number in income. I plan on taking these deductions 401k, IRA, HSA etc. 

Then I can see how much should be due so that I can plan ahead. Also estimating what things I can and cannot qualify for.

Do I just need to grab the proper forms like a K1 1040 etc and do them by hand to guesstimate this?

[respond2u]

I'd grab a CPA : )

If you are planning on making a lot of money, offloading accounting to your CPA will probably have a high ROI at least for year 1.

If you're not planning on making a lot of money it might be easier for you not to incorporate, and just be a sole proprietor. You won't have to pay unemployment taxes that way.

I used a SEP-IRA for me as a sole proprietor and a different SEP-IRA for me as a partner in an LP (one client would only do corp-to-corp). You can contribute something like $55K a year so you don't need to get complicated with 401k and IRA.

I think I could also have done a Keogh to set aside more money, but never bothered with it.

[Heroes821]

I have a CPA, and I use the solo 401k with Vanguard. I just know that I ask a lot of questions of my CPA about how things are calculated and he is always ready to answer at around $125 -$150 an hour.   I trust that my CPA knows what he is doing and that his awesome secret software will do the math properly, I was more or less trying to find something where I could punch my numbers in as I get paid through the year and see how my tax burden changes etc.

I think the only way is to long hand the IRS forms, which I haven't gotten around to trying yet.   I did learn from my CPA recently that as a more than 2% owner of my S-corp I can't deduct my HSA from the FICA portion of my salary, sad but good to know.

[respond2u]

I built a spreadsheet for "good enough" estimated taxes, so I guess I went nearly down the same route you're thinking of. Google sheets is good enough as long as you're not going to do goal seek type work (like "set tax due cell to $X by changing 401k contribution", which excel supports).

I guess the only other thing I'd advise is to buy a copy of TurboTax to validate your understanding. Depending on how deep you want to understand things, you might get by just with that instead of all the IRS instructions.