Data Sources
Every number on USAFinCalc comes from an official, primary U.S. government source — never a third-party estimate or another site's table. Here's exactly where each figure comes from, what it feeds into, and how to verify it yourself.
Primary Sources
These five agencies supply the figures behind nearly every calculator on the site.
Other Sources We Reference
A handful of calculators draw on additional federal data for specifics the five sources above don't cover:
How We Verify Each Figure
A number doesn't reach a calculator just because it sounds right. It follows the same sequence every time:
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Pull it from the primary document
Every figure starts at the source — an IRS revenue procedure, an SSA bulletin, a state Department of Revenue notice, a BLS release, or a FRED data series. We record the specific publication, not a paraphrase of it.
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Build the formula around it
The figure goes into the calculator's logic, then gets tested against a worked example from the same agency — an IRS worksheet, for instance — to confirm the output matches exactly.
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Cross-check where possible
State-level numbers get a second, independent check against the Tax Foundation's tracking before anything ships, to catch a transcription error or an outdated source on our end.
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Publish with a visible date
Every trust page and calculator carries the date it was last reviewed, so it's clear whether a figure reflects the current tax year.
This process is maintained by USAFinCalc's research team. See the editorial policy for the standards behind it.
Update Schedule
| Source | Review frequency | Why |
|---|---|---|
| IRS | Annually, each January | New brackets, deductions & limits release each fall for the coming tax year |
| SSA | Annually, each January | Wage base & FICA figures are announced each October |
| State Tax Agencies | Annually, typically January; ad hoc if a state changes rates mid-year | Most states finalize rates ahead of the new tax year, but some legislate changes off-cycle |
| BLS | As new releases publish (varies by series) | OEWS and CPI update on their own federal release calendars |
| Federal Reserve / FRED | Monthly to quarterly | Mortgage and rate data move throughout the year, not just in January |
Frequently Asked Questions
Where does USAFinCalc get its tax and financial data?
Directly from primary government sources — the IRS, Social Security Administration, individual state tax agencies, the Bureau of Labor Statistics, and the Federal Reserve. We don't use third-party aggregator data for anything that affects a calculator's output.
How often is the data updated?
Federal tax, SSA, and state figures are reviewed every fall and January after official annual releases. Rate-sensitive data like mortgage rates is refreshed more often. Every update carries a visible revision date.
How do you verify a number before publishing it?
Each figure is sourced from the original government document, built into the calculator, then tested against a worked example from the same agency. State-level figures get a second cross-check against an independent tracker like the Tax Foundation before publishing.