Last updated: November 12, 2026
CentMath publishes calculators that people use to make real business and money decisions. This policy sets out the standards every calculator and every page on the site must meet before it is published, and how they are kept accurate afterwards.
Editorial Principles
- Accuracy first. A calculator is published only when its results match published worked examples.
- Show the work. Every result comes with the formula, the meaning of each input and the steps with your numbers.
- Cite the source. Every formula, rate and fee links to the primary source it comes from.
- State the limits. Each calculator explains its assumptions and the cases it does not cover.
Sources We Use
CentMath relies on primary and authoritative sources, in this order of preference:
- Official documentation from the platform or authority that defines the figure, such as ad platform help centers, marketplace fee schedules and payment processor pricing pages.
- Government and regulator publications, such as the IRS, the U.S. Securities and Exchange Commission and the U.S. Small Business Administration.
- Accounting and finance standards bodies and professional references, such as FASB definitions and CFA Institute curriculum material.
- Established textbooks and peer-reviewed research for general formulas.
Other calculator websites, forums and unsourced articles are never used as the basis for a formula or rate.
How a Calculator Is Built
- Research. The search intent is studied so the calculator answers the questions people actually ask, including reverse calculations.
- Formula check. The formula and every constant are confirmed against the primary source.
- Testing. Results are checked against worked examples from the source, then tested at edge cases such as zero values, very large numbers and missing optional inputs.
- Explanation. The page is written in plain language, with examples based on the calculator's own results.
- Final review. The finished calculator and page are reviewed again before publishing.
Fees, Rates and Time-Sensitive Figures
Platform fees, tax rates and thresholds change. Calculators that rely on them show the date the figures were last checked. These figures are reviewed whenever the source announces a change and at least once every quarter.
Use of AI Tools
AI tools may assist with drafting code and text. Every formula, figure and statement is checked by a person against the cited source before publication, and responsibility for the content rests with CentMath.
Independence and Advertising
CentMath does not accept payment to feature, rank or recommend any product, platform or service. If advertising is added to the site in the future, ads will be clearly separated from calculators and content, and advertisers will have no influence over results or editorial decisions.
Authorship and Accountability
All calculators and pages are built and reviewed by Manoj Meena, the founder of CentMath. Each calculator page names its author and shows its last-updated date.
Corrections
When an error is found, it is fixed promptly and the page's last-updated date is changed. Corrections that change a result are noted on the page. See the corrections policy to report an error.