Health & Fitness Calculators
BMI, calories, body composition and wellbeing tools. 17 free tools and counting.
From body composition to training zones, these calculators use the standard published formulas — Mifflin-St Jeor for metabolism, Karvonen for heart-rate zones, WHO cutoffs for waist-to-hip ratio. They are guides for awareness and goal-setting, not medical advice; the FAQ on each tool explains what its number can and cannot tell you.
BMI Calculator
Body Mass Index and weight category from height and weight.
BMR Calculator
Basal metabolic rate — calories burned at complete rest.
TDEE Calculator
Total daily energy expenditure from BMR and activity level.
Calorie Calculator
Daily calories to maintain, lose or gain weight.
Ideal Weight
Healthy weight range for your height.
Body Fat %
Estimate body-fat percentage from BMI, age and sex.
Water Intake
Daily hydration target based on body weight.
Pregnancy Due Date
Estimated delivery date from the last menstrual period.
Macro Calculator
Protein, carbs and fat grams from a daily calorie target.
Ovulation Calculator
Estimate your fertile window from your last period and cycle length.
Pace Calculator
Running pace and speed from distance and time.
One-Rep Max
Estimate your 1RM and training loads from a lift.
Heart Rate Zones
Training zones from your age and resting heart rate.
Waist-to-Hip Ratio
WHR and health-risk category from waist and hip measurements.
Steps to Distance & Calories
Turn a step count into distance walked and calories burned.
Calories Burned Calculator
Energy burned by an activity, based on MET values, weight and duration.
Lean Body Mass Calculator
Estimate lean mass and fat mass from height, weight and sex.