Health & Fitness Calculators
Calculate BMI, daily calories, and body fat percentage — private, browser-based estimates with no account required.
Health and fitness numbers — body mass index, daily calorie needs, body fat percentage — are useful for setting goals and tracking progress, but the formulas behind them are fiddly to compute by hand and many sites bury the answer behind sign-up forms and ads.
These calculators give you the estimate immediately, in imperial or metric units, and run entirely in your browser. The personal measurements you enter never leave your device, so there is no privacy trade-off for a quick check.
Everything here is for general information only and is not medical advice. The formulas are population averages — your individual numbers may differ. For anything that affects your health, consult a qualified professional.
Calculators in this category
BMI Calculator
Calculate your Body Mass Index from height and weight in imperial or metric units, with category ranges.
Open calculator →Calorie Calculator
Estimate your daily calorie needs (TDEE) from age, sex, weight, height, and activity level using the Mifflin–St Jeor formula.
Open calculator →Body Fat Calculator
Estimate body fat percentage from body measurements using the U.S. Navy method, in imperial or metric units.
Open calculator →Frequently Asked Questions
Are these health calculators medical advice?+
No. BMI, calorie, and body fat calculators give general estimates based on population formulas. They do not account for muscle mass, body composition, medical conditions, or individual variation, and they are not a diagnosis. For health decisions, talk to a doctor or registered dietitian.
Is my health data private?+
Yes. Every calculator runs entirely in your browser. The figures you enter — weight, height, age, measurements — are never sent to a server and are never stored. Refreshing the page clears everything.
Why does BMI have known limitations?+
BMI is a simple ratio of weight to height. It is a useful population-level screening number, but it cannot tell muscle from fat, so very muscular people can register as "overweight" while others within a "normal" BMI may carry excess fat. Use it as one signal among several, not a verdict.
What is TDEE and why does it matter?+
TDEE (Total Daily Energy Expenditure) is an estimate of how many calories you burn in a day, including activity. It is the baseline for managing weight: eat around your TDEE to maintain, below it to lose, above it to gain. The Calorie Calculator estimates TDEE using the well-validated Mifflin–St Jeor equation.