Accuracy
Every calculator is tested against worked examples that can be verified by hand, and those examples are published on the page. Unit conversions use exact definitions where they exist, such as one inch being exactly 2.54 centimeters. Where a figure is a typical value rather than an exact one, such as the weight of a cup of flour, the page says so.
Sources
Where a page relies on an official rule, for example Social Security retirement ages or BMI categories, we name the organization and encourage you to check its website for your own situation. Rules and figures can change, so each page shows when it was last updated.
Corrections
If you find an error, tell us through the contact page. We check every report, fix confirmed mistakes promptly and update the page's date.
Use of AI
We use AI tools to help draft explanations and guides. Content is tested and edited before publication, but no tool is perfect, so please report anything that looks wrong.
Not professional advice
Calculators and guides are for general information. They are not medical, financial, tax or legal advice. Results are estimates, and you should speak to a qualified professional before making important decisions.
Advertising
We may show ads served by third parties, including Google. Advertising does not affect our calculations, and we do not accept payment to change a result or a recommendation.