What MoneyOrNot is
MoneyOrNot is a set of calculators for everyday money decisions: saving and investing, borrowing, retirement and valuation. Most of them solve for whichever number you leave blank, so you can start from a goal as easily as from a budget. They run entirely in your browser; see the privacy policy.
Editorial policy
Accuracy
Every calculator is built from published formulas, documented on the methodology page, and checked by automated tests: hand-worked textbook cases, round trips (solve for a value, then solve back), edge cases such as 0% rates and negative returns, and checks that the page never shows an impossible or non-finite number. Worked examples on each page are computed by the calculator itself, and tests confirm each example link shows the figure the text promises.
Sources
Historical data comes from primary sources: the U.S. Bureau of Labor Statistics (Consumer Price Index), Robert Shiller’s U.S. stock market data (S&P 500 returns and dividends) and the IRS (tax brackets and contribution limits). Each page links its methodology, and the data sources are listed with their coverage on the methodology page.
Updates and corrections
Each calculator page shows the date it was last updated. We review pages when tax rules, contribution limits or data change, and when a calculation or explanation is found to be wrong. Material corrections are made promptly and the page’s date is updated.
Independence and advertising
MoneyOrNot may show advertising to keep the calculators free. Advertisers have no say in what we write or how anything is calculated, and no calculator is designed to steer you toward a product. Ads, when shown, are labeled and kept separate from results.
Not advice
Results are educational estimates based on the assumptions you enter. They are not financial, tax, legal or investment advice. For decisions with significant consequences, check your numbers with a qualified professional.
How the calculators are built
Each page is plain HTML with a small amount of JavaScript and no tracking of what you type. Exact formulas are used wherever they exist; when an answer has no formula, such as a required rate of return, it is found with a bounded search that can’t run away or loop forever. The details, including rounding conventions, are on the methodology page.