Skip to content
Client portal Knowledge Hub About Send an inquiry
James StillionCPA Find a calculator Inquire

Calculators

Free tools built by the CPA who prepares the returns. Each one lists the rules and figures it uses.

All 12 calculators

Most used

S-Corp vs. Sole Proprietor ›1099 Estimated Tax Planner ›Withholding Checkup ›
When a tool isn’t enoughEvery calculator links to the service or model that covers the rest of the question.Send an inquiry

Models

Excel workbooks for reporting and tax analysis. Licensed per user or firm; you own your copy.

All models

What’s inside

21 tabs, 28,550 formulas (FRP) ›§1374 and LIFO recapture (C→S) ›Pre- and post-2025 §1202 rules ›
Rather have me run it?I can build the reporting package or run the analysis as an engagement.Send an inquiry
About

James Stillion, CPA

A sole practice. I do the work myself.

LicenseCalifornia 157015
Based inTorrance, CA
ClientsLA and remote

How I work

I'm a CPA licensed in California (license 157015). I practice as a sole practitioner, so you deal with me from the first email to the filed return. Nothing is handed off to staff you've never met.

I work alongside founders, owner-run businesses, S-corporation owners, real estate investors, contractors and individuals, on the numbers behind their decisions as well as the returns and the books. Most clients are in the Los Angeles area; I also work with clients remotely across the country, after confirming the state filing requirements are within my scope.

What I focus on

  • Individual and S-corporation tax returns, and planning between filing seasons
  • Monthly accounting and closes in QuickBooks Online, including job costing for contractors
  • S-corporation elections, reasonable compensation and entity setup
  • Financial reporting packages and technical accounting: leases (ASC 842), consolidations (ASC 810) and business combinations (ASC 805)
  • Financial models, including Excel workbooks I sell on this site

I don't prepare C-corporation or partnership returns, and I don't perform audits.

How an engagement starts

Every engagement starts with a signed engagement letter setting out the scope and fee, family and referrals included. If the work involves a tax return, the IRC §7216 consent forms come with it as separate documents. Documents are exchanged only through the secure client portal.

Tools and models

The free calculators on this site and the Excel models come out of the same work: questions clients ask often enough that they deserve a proper tool.

When the answer needs judgment, ask me.

Send a few sentences. If it fits, you get an engagement letter with the scope and fee, and the IRC §7216 consent forms. Documents go through the secure portal.

Send an inquiry