Our Editorial Standards & Tax Methodology

Last reviewed: July 8, 2026 · Primary sources: IRS Pub. 334, 505, 535, 587, 15 · State rates from official Department of Revenue publications.

Who We Are

SelfEmpTaxCalc is built and maintained by an independent software team that develops free, privacy-first calculation tools for freelancers, gig workers, and independent contractors. Every calculator runs entirely in your browser — nothing you type is uploaded or stored on a server. We are not a tax firm and we do not employ the calculators to give advice; we build the math so you can explore scenarios before talking to a professional.

How We Build the Calculations

Our numbers follow published U.S. federal and state tax rules. The methodology is documented and reproducible:

Self-employment tax uses the 15.3% rate (12.4% Social Security up to the annual wage base, 2.9% Medicare with no cap, plus the 0.9% Additional Medicare Tax above the threshold) — per IRS Pub. 334 and Pub. 15.
Quarterly estimated payments follow the annualized income / prior-year safe-harbor methods in IRS Pub. 505.
Business deductions (home office, mileage, equipment, write-offs) reflect the rules in IRS Pub. 535 and Pub. 587.
Retirement deductions (SEP, Solo 401(k), SIMPLE) follow IRS Pub. 560.
State income tax uses each state's official bracket or flat rate as published by that state's Department of Revenue for the 2026 tax year. Where a state applies brackets to federal AGI minus a state-specific deduction, our tool applies brackets to net self-employment earnings as a documented simplification (noted on each state page).

How Often We Review

Tax law changes every year. We review all calculators and state guides annually before each filing season and update rates, thresholds, and due dates as soon as the IRS or a state revenue department publishes them. Each page carries a "Last reviewed" date so you can see how current the figures are. If you spot a figure that looks outdated, tell us and we will verify it against the source.

What This Tool Is — and Is Not

Our calculators produce educational estimates to help you plan. They are not a substitute for a licensed CPA, Enrolled Agent, or tax attorney, and they do not file anything with the IRS. Real tax returns involve credits, dependents, multi-state situations, and basis rules that a simple estimator cannot capture. Always confirm your final numbers with a qualified professional before filing.

Editorial Independence

We do not accept payment to change a calculation result or to recommend a specific tax product. Calculator outputs are driven by the published formulas above, not by advertising. The site is supported by contextual advertising, which is kept separate from the calculation logic.

Corrections & Sources

Every figure links back to its primary source where possible. For the full list of IRS publications and state authorities we rely on, see our Reference Sources & Citations page. If you find an error, contact us — we correct verified mistakes promptly and note the change date.

Related Calculators

Our Methodology

We centralize every variable rate — federal brackets, SE tax, standard deduction, QBI, CTC, and all state rates — in a single configuration file. The calculators read from that file, so a verified update propagates across the entire site at once rather than being hand-edited page by page.

Sourcing & Verification

Update Cadence & Corrections

We review rates at the start of each tax year and whenever a controlling agency announces a change. When we correct a figure, we update the config file and note the "last reviewed" date on affected pages. If you spot a discrepancy, our contact page is the fastest way to reach us.

Independence

Editorial content is written to help freelancers understand their obligations; it is not influenced by any platform or advertiser. Where we link to a related tool we operate, it is disclosed.