Health & Fitness Calculators
Free tools to calculate your BMI, daily calories, ideal weight, macros, body fat and more. Instant results, no registration, based on scientific evidence and WHO criteria.
BMI Calculator
Body Mass Index per WHO criteria. Category, healthy weight and personalised recommendations.
Ideal Weight
Your healthy weight range by height and sex. Devine, Robinson formulas and WHO range.
Daily Calories
TDEE and BMR by activity level and goal: deficit, maintenance or surplus.
Calories Burned
Caloric expenditure by exercise type, weight and duration.
Macro Calculator
Optimal distribution of proteins, carbohydrates and fats for your nutritional goal.
FFMI Calculator
Fat-Free Mass Index. Key reference for strength athletes and bodybuilders.
Body Fat %
Body fat percentage using the US Navy formula. Valid for men and women.
Daily Water
Recommended daily water intake by weight, activity level and condition.
About the tools
What are health and fitness calculators?
Tools based on clinical formulas validated by organisations such as the WHO, the NIH and the US Navy. They let you know key health and fitness indicators in seconds, without visiting a professional or buying specialised equipment.
Evidence-based
Mifflin-St Jeor and Harris-Benedict for TDEE, WHO criteria for BMI, Devine and Robinson for ideal weight, and the US Navy formula for body fat.
100% private
All calculations happen in your browser. No data stored, no registration, and no information is sent to external servers.
Instant result
Enter your data and get the result instantly. No extra steps, no waiting, no intrusive ads.
Frequently asked questions
All about health calculators
Which health calculator should I use first?
The most common starting point is the BMI calculator to find out if your weight is healthy relative to your height. Then use the daily calories (TDEE) calculator to know your energy expenditure. With those two references you can use the rest of the tools depending on your goal: losing fat, gaining muscle or simply maintaining.
Are these calculators reliable?
Yes. All use scientifically validated formulas: WHO criteria for BMI, Mifflin-St Jeor and Harris-Benedict for TDEE, Devine and Robinson for ideal weight, and the US Navy formula for body fat. They are guidance tools and do not replace individual medical assessment.
What is the difference between BMI and body fat percentage?
BMI is a mathematical ratio between weight and height; it doesn't distinguish between muscle and fat. Body fat percentage directly measures what proportion of your body is adipose tissue. For athletes or muscular people, body fat % is a more precise indicator — they can have an overweight BMI without actual excess fat.
How do I calculate my calories to lose weight?
Use the daily calories calculator and enter your weight, height, age, sex and activity level. The result will be your total daily energy expenditure (TDEE). For progressive and healthy weight loss, create a 300–500 kcal deficit from that value. Complement with the macro calculator to optimally distribute those calories between proteins, carbohydrates and fats.
What is the FFMI calculator for?
The FFMI (Fat-Free Mass Index) measures muscle development by removing the influence of body fat. It is especially useful for strength athletes and muscular people who get misleading BMI values. An FFMI above 25 in men is considered very difficult to achieve naturally.
Do I need to register to use the calculators?
No. All calculators are completely free and require no registration, account or subscription. Calculations are performed directly in your browser and no data is sent to external servers. Your information is 100% private.
