How We Calculate
- Author
- CentCompass
- Last Updated
- Reading Time
- 1 min read
Each calculator is powered by a small, pure calculation engine that is unit-tested against known results. Investment growth uses standard compound-interest math; loans and mortgages use the standard amortization formula; income tax applies the federal progressive brackets; payroll uses Social Security and Medicare (FICA) rules.
Dated, sourced data
Tax brackets, the standard deduction, FICA parameters, and contribution limits are tied to a specific tax year and stored in a single source of truth. We never duplicate these figures across the codebase. See the data sources page for the official references and review status.
Limitations
Calculators provide estimates. Tax tools currently cover federal rules only and do not include state taxes. Results are educational and do not replace professional advice.
Sources
How this page is produced
Editorial process. CentCompass is maintained independently, and this page is written and checked against the official publications listed above before it goes live. There is no separate editorial reviewer. This page was last checked on . See our editorial policy.
How the calculations work. Every result comes from a small, unit-tested calculation engine rather than a spreadsheet or a hardcoded table. Loans use the standard amortization formula, growth uses compound-interest math, income tax applies the federal progressive brackets, and payroll applies Social Security and Medicare rules. Our methodology sets out each one.
Where the figures come from. Tax brackets, standard deductions, FICA parameters, and contribution limits are stored once in a dated registry and read directly by the calculators — the same values appear in the text above, so the two can never drift apart. Each figure records its source, effective tax year, and review status on our data sources page.
Update policy. Regulatory figures are checked against their primary source when the IRS, SSA, or another authority publishes new values — typically each autumn for the following tax year — and again at the scheduled review date recorded for each dataset. Figures that have not been checked yet are marked as draft on the data sources page until that check is complete.
Educational purposes only — not financial, tax, or investment advice (disclaimer).