About This Site

What we do

We build calculators that show their work. Every tool on this site states the equation it uses, the units it expects, how inputs are converted, and what the result does and does not represent. Where a calculation is an estimate produced by a population equation, we say so on the page.

What we do not do

• We do not provide medical advice, diagnosis or treatment.
• We do not claim clinical accuracy for any individual person.
• We do not publish invented statistics, testimonials or expert endorsements.
• We do not sell or share the values you enter — calculations run in your browser.

Editorial approach

Content is written in clear US English and kept as short as the topic allows. A page is published only when the calculator on it is genuinely useful and the surrounding explanation adds something a search result would not already answer. See our methodology page for the equations we use.

Contact

Corrections and questions are welcome through our contact page.