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Solo1099
About

About Solo1099

Solo1099 is a small set of free, accurate tax calculators built for the 60+ million Americans who file their own 1099 income.

Why this site exists

Most online tax calculators were built to capture leads for tax-prep software. They run a quick estimate, then funnel you into an upsell. The numbers are often stale, the math is rarely shown, and the result is a marketing-shaped answer rather than a planning-shaped one.

Solo1099 takes the opposite approach. The calculators here are open about the math, source every figure to the IRS or SSA publication that produced it, and never ask you for a phone number or email to see the result. The whole tool runs in your browser; nothing is sent to a server.

How the calculators are built

Every calculator is a thin React component on top of a pure-function tax engine. The engine takes structured input (income, expenses, filing status, year), looks up the IRS tables, and returns a structured result that the UI renders.

That separation makes two things easy:

  • Auditable math. The same compute function powers every page. If we are wrong, we are wrong everywhere — and a single fix corrects the whole site.
  • Annual updates. The IRS publishes inflation-adjusted brackets every fall (typically October). Updating the figures means changing one file and verifying against the new Revenue Procedure.

Where the numbers come from

The data behind the calculators is drawn from public, primary sources:

  • IRS Revenue Procedures. Tax brackets, standard deductions, Section 199A thresholds and most other inflation-adjusted figures. The most recent is Rev. Proc. 2025-32 (IRB 2025-45) for tax year 2026.
  • SSA COLA fact sheets. The annual Social Security wage base, on which the 12.4% portion of SE tax is capped. See the 2026 COLA fact sheet.
  • Internal Revenue Code (Title 26). The legal foundation behind every figure. Most relevant: § 1402 (SE tax), § 199A (QBI), § 6654 (estimated tax safe harbors).
  • Form 1040 instructions and Schedule SE. The official computation worksheets.

What we do not do

  • We do not file your taxes. Solo1099 is a planning aid, not a return preparer. When the time comes to file, you will use IRS Free File, TurboTax, FreeTaxUSA, or a CPA.
  • We do not give personalized tax advice. Every situation has edge cases. For decisions that affect your actual return, talk to a licensed CPA, EA, or tax attorney.
  • We do not store your inputs. Every calculator runs entirely in your browser. No numbers leave your device — there is no backend that could log them even by accident.
  • We are not affiliated with the IRS or any government agency. Linking to IRS.gov resources does not imply endorsement.

Roadmap

The next pieces we are building, roughly in priority order:

  • Schedule C deduction walkthroughs by industry.
  • Take-home pay calculator for 1099 income (federal + state).
  • Solo 401(k) vs SEP IRA comparison tool.
  • Mileage and home-office deduction calculators.

If you would find one of those especially useful, the fastest way to bump it up the list is to drop a note.

Disclaimer

Solo1099 provides general tax information for educational purposes. It is not a substitute for personalized advice from a licensed CPA, EA, or tax attorney. Tax law changes frequently — verify figures with the IRS before filing. Use of the calculators does not create any professional relationship.