Solo-operator finance math without the
CPA-mill agenda.

Most calculators online for self-employed operators are run by tax-prep services, payroll vendors, or affiliate aggregators with a commission on the answer. This site is the opposite: every formula is open-source, every assumption cites the primary source (IRC sections, IRS Publications, Treasury regulations), and every tool is reviewed quarterly by a named operator. Built for freelancers, creators, contractors, and sole proprietors — anyone earning self-employment income on Schedule C or pass-through-entity 1040.

Retirement Savings

• Solo 401(k) vs SEP-IRA Contribution Comparator

  Compare maximum annual contributions: Solo 401(k) (employee + employer-side per IRC §401(k)/§415) vs SEP-IRA (employer-only per IRC §408(k)). Solo 401(k) usually wins for self-employed earning under ~$300K because the employee portion stacks on top. Cited to IRS Pub 560, IRC §401(k), §408(k), §415(c).

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Entity Structure

• LLC vs S-Corp Self-Employment Tax Decision

  Compute the net-income threshold at which an S-Corp election saves more in self-employment tax than the compliance overhead costs (payroll setup, additional filings, reasonable salary administration). Cited to IRC §1366, §3121, IRS Rev. Proc. 2013-30 (late-S-Corp election relief).

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Tax Deductions

• QBI Deduction Calculator

  Compute the IRC §199A Qualified Business Income (QBI) deduction — 20% of qualified pass-through business income, with the wage-and-property limitation phase-in at $232,500 single / $464,200 married-filing-jointly thresholds (2025). Specified Service Trade or Business (SSTB) phase-out logic included. Cited to IRC §199A, Reg §1.199A-1 through §1.199A-6.

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