Our Methodology
This page explains how CalcFalcon's calculators are built, where the numbers come from, how often we check them, and what happens when we find a mistake. We publish it because financial estimation tools are only useful if you can trust the math behind them — and trust starts with showing our work.
How We Build a Calculator
Every calculator starts from a documented formula, not a guess. For tax calculators, that means working from the relevant IRS publication or Revenue Procedure line by line — tax brackets, standard deductions, FICA rates, the self-employment tax's 92.35% adjustment, capital gains bracket stacking, and Net Investment Income Tax thresholds are all implemented directly from primary IRS sources, not third-party summaries. For platform-fee calculators (YouTube AdSense, Etsy, DoorDash, Airbnb, and similar), we start from the platform's published fee schedule and terms.
Each formula is implemented as a pure, isolated function, separate from the interface that collects your inputs. That separation lets us test the math on its own and update a rate or bracket in one place without touching how the calculator looks or behaves.
Where Our Tax Data Comes From
Every tax and finance calculator that cites IRS figures displays a visible "Sources & Last Updated" block directly on the calculator page. It names the specific IRS publication, Revenue Procedure, or Social Security Administration fact sheet the numbers come from, states which tax year the figures apply to, and gives the date we last checked them against that source. If you're ever unsure whether a number is current, check that block before you check anything else on the page.
Review Cadence
Federal tax brackets, standard deductions, and Social Security wage bases are set annually by the IRS and SSA, typically announced in the final months of the preceding year. We review our tax calculators against the newly published figures each time the IRS releases them and update the "Sources & Last Updated" date accordingly.
In practice that means an annual pass over every tax calculator once the IRS publishes the new year's Revenue Procedure, and a review of platform-fee calculators whenever a platform announces a pricing change. Rather than claim a cadence we can't prove, each calculator states the tax year its figures cover and the date those figures were last checked, so you can judge for yourself how current a given page is. If a calculator's stated tax year is behind the current filing year, treat its output as a historical estimate and verify against current IRS figures before relying on it.
How We Correct Errors
If you find a figure that looks outdated, a formula that looks wrong, or a broken calculator, please tell us at hello@calcfalcon.com or through our contact form. We verify the report against the primary source, fix the underlying formula or constant if it's wrong, and update the calculator's "Sources & Last Updated" date to reflect the correction. We do not silently edit published figures without updating that date — if the numbers on a page changed, the date changes with them.
What Our Calculators Are Not
Our calculators are general-purpose estimation tools. They cannot account for every detail of your individual situation — state-specific rules, prior-year carryovers, credits you may qualify for, or circumstances a form field doesn't ask about. Read our full financial disclaimer for what that means before you rely on a result.
Editorial Independence
CalcFalcon is supported by display advertising and affiliate partnerships — see how we make money for the full breakdown. Affiliate relationships never change what a calculator computes. A calculator's math is the same whether or not an affiliate link appears next to it.