About LeanGauge

LeanGauge offers free fitness and nutrition calculators (calories, macros, protein, BMR, BMI and more) — fast, free, and with no signup required.

We built LeanGauge because getting a straight answer to a simple question shouldn't require wading through ads, popups, or long articles. Every tool on the Site gives you a clear result in seconds.

Where the equations come from

None of LeanGauge's formulas were invented by us — every one comes from an equation published and reviewed within the nutrition and exercise-physiology literature:

• TDEE and BMR: the Mifflin-St Jeor equation (Mifflin MD, St Jeor ST, et al., American Journal of Clinical Nutrition, 1990), one of the most studied for adults in general and closer to real expenditure than the older Harris-Benedict equation (1919), which tends to overestimate. When you enter your body fat %, we use Katch-McArdle (based on lean mass). Every formula is an estimate, with a margin of about 10%.
• Protein: the 1.6–2.2 g per kg bodyweight range is supported by International Society of Sports Nutrition (ISSN) reviews on protein intake for active individuals.
• BMI: the standard World Health Organization cutoffs (under 18.5 / 18.5–24.9 / 25–29.9 / 30+).
• Calorie deficit: the classic ~7,700 kcal per kg of body fat approximation (Wishnofsky, 1958). It's a widely used simplification — more recent research shows the body adapts over time, so we treat the result as a starting estimate, not an exact guarantee.
• Food and meals: nutrition values from the full Brazilian TACO food composition table (4th ed., NEPA/UNICAMP) and USDA FoodData Central. Branded products come from Open Food Facts, a community database: they're labeled on the site and worth checking against the package.

Where the science gives a range rather than one single number (like protein or hydration), we pick a value inside the recommended range — and say so on the calculator's own page, instead of hiding the simplification.

Our approach

All of our calculators run directly in your browser, so your inputs (weight, height, goals) stay on your device — only food searches query our database, and only people who create an account have saved meals stored with us. We keep the interface clean and the math transparent, and we explain what each result means so you can use it with confidence, instead of just spitting out a number.

How we keep this current

We periodically review the equations and ranges used in each calculator against current literature. When a guideline changes (say, an update to protein or hydration recommendations), we update the corresponding calculator and its explanatory text.

A note on accuracy

LeanGauge provides general educational estimates and is not medical or nutritional advice. No equation — ours or a paid app's — replaces individual assessment. Consult a qualified professional before making significant changes to your diet or training.

Get in touch

Feedback, found an error in a calculation, or want to suggest a calculator? Reach us on our contact page — we reply personally.