Who this site is for
Freelancers, independent contractors, sole proprietors, consultants, content creators, and side hustlers with 1099 income share one problem: no employer withholds taxes on their behalf, and no HR department sends a W-2 at year-end. That gap creates real uncertainty around quarterly estimated payments, self-employment tax, and effective rates at different income levels.
FreelanceMath is built for that audience. The calculators are designed for scenario testing, running numbers before committing to a rate, accepting a contract, or setting aside money for a quarterly payment. They work best when paired with the short guides on the same topic, which explain the tax concepts behind each figure the calculator produces.
How editorial content is produced
Every page on FreelanceMath starts with a research phase: identify the specific freelancer tax question the page will answer, then locate the controlling IRS or SSA primary source before a single word of calculator logic or explanatory prose is drafted.
From there, the pipeline moves through these stages: draft the calculator logic against the primary source figures; write the supporting guide content in plain US English; cross-check all constants and rates against other published pages on the site to catch inconsistencies; and publish with a visible last-updated date. No page is published without a confirmed primary source for every figure it uses. FreelanceMath does not operate as a personal blog. There are no named authors, no individual bylines, and no "Reviewed by" credits. The project publishes as FreelanceMath, and the editorial standards described here apply to every page on the site.
Calculation methodology framework
The calculators on FreelanceMath model the federal self-employment tax stack that applies to Schedule C and Schedule SE filers: net self-employment income, the deductible portion of SE tax, the 15.3% combined Social Security and Medicare rate (applied to earnings up to the SSA wage base, with the 2.9% Medicare portion continuing above it), and progressive federal income brackets from IRS Revenue Procedure 2025-32.
All math runs in the browser. No data is sent to a server. Constants (the SSA wage base, bracket thresholds, standard deduction amounts, and SE tax rate) are updated each tax year from published IRS and SSA sources. For a full breakdown of the calculation steps, the specific IRS and SSA sources used, per-tool methodology notes, and known limitations of each calculator, see the full methodology details.
Want to see exactly how the calculators are built? The Methodology page documents the IRS and SSA sources behind each figure, the calculation steps for each tool, per-tool notes on scope and assumptions, and a plain-language description of known limitations. Start there if you need to verify a specific number or understand what a calculator does and does not model.
Source verification standards
Acceptable primary sources for any figure on FreelanceMath are: IRS.gov publications and form instructions (including IRS Publication 334, IRS Publication 505, and Schedule SE instructions), published Revenue Procedures (such as Rev. Proc. 2025-32 for 2026 inflation-adjusted figures), SSA.gov wage base and COLA announcements, and state revenue department rate tables for any state-specific content.
Secondary sources (tax-prep brand blogs, financial media, or aggregator sites) are not used as sole citations for any figure that appears in a calculator or guide. Every URL used to source a figure is checked before that figure goes live. Any figure that cannot be traced to a primary source is either omitted from the page or flagged internally for resolution before publish. That standard applies to every page, including this one.
Review and update cadence
Annual figure refreshes happen each October and November, when the IRS publishes its inflation adjustments for the coming tax year and the SSA announces the updated Social Security wage base. For 2026, the relevant publications were IRS Revenue Procedure 2025-32 (released October 9, 2025) and the SSA's wage base announcement setting the 2026 taxable maximum at $184,500.
When the IRS issues material guidance changes that affect a calculator mid-year, affected pages are updated within one week of that publication date. If an error is discovered on any page at any time, the correction is made immediately and the last-updated date on that page is revised to reflect it. The same schedule applies to all calculator and guide pages across the site.
Tools, guides, and how to use them
FreelanceMath publishes two types of content: free freelance tax calculators and freelancer tax guides, and they are designed to be used together. Run a scenario in the calculator first, adjust income, filing status, or quarterly payment, then read the companion guide to understand what the output means and why the underlying tax rules work the way they do.
All core calculators are accessible without creating an account or providing an email address. For an overview of the tax topics covered across the site, the freelance tax resources category hub organizes content by subject area.
Contact
To report a calculator bug, flag an outdated tax figure, or suggest a guide topic, email freelancemath.mail@gmail.com. The information on this site is general in nature and is intended for educational and planning purposes only, it is not tax or financial advice.