BMI, calories, TDEE, macros, body composition, heart rate and pregnancy calculators built on published formulas from the WHO, CDC, NIH and the Institute of Medicine — 30 free tools, no signup, with the formula and sources shown on every page.
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Published equationsMifflin-St Jeor, WHO, CDC, IOM
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Sources on every pageFormula, method and last-checked date
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Most-Used Calculators
Start here — most health goals begin with body size and daily energy needs.
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BMI Calculator
Body mass index and adult weight category from your height and weight.
Builds and maintains every CalculatePilot calculator, checking each formula against its original published source and re-verifying pages on a regular schedule.
Every calculator shows its formula and the organization or paper it comes from. We don't invent thresholds or claim testing we haven't done — and these tools give estimates, not medical advice.
WHO — BMI classification & Asian cut-offs (Lancet, 2004)CDC — adult BMI categoriesMifflin et al., Am J Clin Nutr 1990Institute of Medicine — Dietary Reference IntakesIOM 2009 — Weight Gain During PregnancyAHA/ACC 2025 high blood pressure guidelineHodgdon & Beckett — U.S. Navy body fatWidmark — blood alcohol
Frequently asked questions
Why does BMI have different cut-offs for Asian populations?expand_more
A 2004 WHO expert consultation found that many Asian populations have a higher proportion of body fat and higher risk of type 2 diabetes and heart disease at a lower BMI than European populations. It kept the international categories but proposed additional public-health action points of 23 (increased risk) and 27.5 (high risk) for Asian populations.
Why check waist-to-height ratio as well as BMI?expand_more
BMI can't tell muscle from fat or show where fat is stored. Waist-to-height ratio reflects fat around the middle, which is more closely linked to heart and metabolic risk. A common guide is to keep your waist to less than half your height (a ratio below 0.5).
Is the 3,500-calorie rule accurate for weight loss?expand_more
Only as a rough starting point. The idea that a 3,500-calorie deficit always removes one pound of fat assumes your energy use stays constant, but it falls as you lose weight, so loss usually slows over time. Treat any weight-loss timeline as an estimate and adjust it from your actual progress.
Do these calculators store my health data?expand_more
No. The calculations run in your browser and the numbers you enter aren't sent to or stored on our servers. Like most websites, the site itself uses analytics and advertising cookies — see our privacy policy for details.
Are these calculators medical advice?expand_more
No. They use published formulas to give estimates for general information. Results can be less accurate for children, pregnant women, older adults and athletes; talk to a doctor or registered dietitian about decisions for your health.
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