About this site
tdeecalculator.fitness is an independent calculator built and maintained by Alton Vieira. It exists because most TDEE calculators hand you a single number with no formula, no range, no help with the one input that matters most (your activity level), and often a sales funnel underneath.
Here the equation is shown with your numbers in it, the result comes with the error band it deserves, the activity picker asks about your job and your steps instead of only your workouts, and the tracker lets you replace the estimate with a measured one. Nothing you enter leaves your browser.
Who is behind it
Alton Vieira builds small, fast reference tools for US readers. I am not a physician or a registered dietitian, and the site does not claim a medical review it has not had. What it does claim is that every formula, constant and threshold is taken from a named, linked source, that the math is tested, and that nothing on the page is invented to look authoritative. The methodology page lists all of it.
How the numbers are checked
One small engine computes every value on the site: the examples in the text, the chart, and the live calculator all run the same code. The engine has automated tests against the published equations and hand-worked cases, and the site will not build if a page and the engine disagree. Published PubMed references were verified against the National Library of Medicine record (title, authors, journal, year) before being cited.
What it is not
Not medical advice, and not a substitute for a clinician or dietitian if you are pregnant, under 18, recovering from an eating disorder, or managing a condition that affects weight. Not a diet program: there are no meal plans, supplements, consultations or apps for sale, and no email list.
Found a mistake?
Write to hello@tdeecalculator.fitness with the page and the number that looks wrong. Corrections are checked against the sources and fixed in the engine, which fixes every page that uses the value.