What this site exists for
Most fitness calculators on the web are wrappers around a single equation, with marketing pages on top. We wanted to build the opposite: implement every commonly cited formula, explain when each one works, and pair the math with deep, evidence-cited guides on what to do with the result.
No accounts. No upsells. No "premium" calculator with the ad-free version locked behind a $9 paywall. Every calculation runs in your browser — your data never leaves your device.
What you get
15+ scientific calculators
TDEE, BMR (three formulas), macros, body fat (multiple methods), lean mass, FFMI, protein, water, BMI, bulking, cutting, deficit, and reverse dieting.
Personalized to your profile
Age, sex, body weight, body fat %, activity level, training experience, and goal — all of it changes the answer, and the calculators handle it transparently.
Long-form, evidence-cited guides
Each calculator pairs with a 4,000–10,000-word guide explaining the science, the trade-offs, and what to actually do day-to-day.
Privacy-first by default
No accounts. No tracking pixels beyond Google Analytics with anonymized IP. All calculations run in your browser — health inputs never touch our servers.
How we are different
Every claim cites a source
Quantitative claims (calorie counts, multipliers, percentages) are tied to either the originating equation or a peer-reviewed paper. If we cite a number, we link the source.
Editorial review before publication
Every guide is fact-checked against the cited sources before publication. When an article has been reviewed by a named expert their name and credentials appear at the bottom; otherwise the article carries only the editorial-team attribution.
Updated when evidence changes
When a major position stand is published or revised (for example, an updated ISSN protein recommendation), affected guides are revised within 60 days.
For the full editorial process — sources, review cycle, and correction policy — see our editorial standards page.
Sources we cite
Our guides cite primary literature wherever possible and rely on position stands and clinical guidelines from the bodies below.
What this site is not
This is not medical advice. Calculator results are estimates for general fitness and education. They are not a substitute for evaluation by a clinician or registered dietitian.
For medical conditions affecting metabolism — PCOS, thyroid disease, diabetes, eating-disorder history, pregnancy, or any condition requiring personalized planning — please consult a qualified healthcare professional. Find one through the Academy of Nutrition and Dietetics.
This is not a meal-delivery service. If you want a meal plan handed to you, this is not the right site. If you want to understand the math behind calorie targets, macros, and goal-setting — and then build something yourself — this is exactly the right site.
Have feedback or a correction?
We respond to correction requests within 7 days. Let us know what you found, where you found it, and a source we should consider.