Financial math you can inspect.

Plain Finance Tools

Editorial responsibility

Plain Finance Tools publishes and maintains the calculators and educational guides on this site. They use documented methods and reproducible examples and are not independently reviewed by a financial professional.

To question a calculation or request a correction, email support@plainfinancetools.com.

Our approach

We show the starting amount, total deposits, and projected interest separately, with a schedule you can inspect. The method page explains each formula, examples you can reproduce, and the factors the models do not include.

The calculation engines are checked with reproducible examples and automated tests. Coverage includes fixed-rate loan amortization, CD maturity values, compound growth, savings targets, unusual rates, payment or deposit schedules, invalid inputs, and keyboard use. These checks do not turn an estimate into a prediction or a financial recommendation.

What is available today

Use the loan calculator to estimate payments and amortization, the CD calculator to estimate certificate earnings, the compound interest calculator to project a plan forward, or the savings goal calculator to solve for a recurring deposit or timeline. The tools do not hold accounts, recommend products, or collect the amounts you enter. See our privacy information for how the site handles data.

Learn before comparing scenarios

The learning center connects plain-language explanations with the relevant calculator. Each page identifies assumptions, includes an example, and links to the full calculation methodology.

Publishing, updates, and corrections

Plain Finance Tools publishes and maintains the calculators and educational pages on this site as an independent project. Calculator pages identify their latest substantive update and link to the shared method, limitations, and privacy boundaries. Automated tests check reference cases, but they are not a substitute for an independent professional review.

If you find a possible calculation, explanation, or accessibility problem, email support@plainfinancetools.com. We assess corrections against a reproducible input, the documented method, and the relevant test case before release. We do not use an “expert reviewed” label unless a real reviewer and review process can be identified.