Calculator categories
Health
BMI, calories, water intake, ideal weight, BMR. 5 free calculators with the formula, worked examples, and FAQ on every page. All math runs in your browser — nothing is sent to a server.
BMI calculator
Body Mass Index from weight and height, with WHO category labels
Calorie / BMR calculator
Basal metabolic rate (Mifflin–St Jeor) and daily calorie targets for maintenance and weight loss
Water intake calculator
Daily water target from body weight and exercise level, in liters, ml, cups, and fluid ounces
Body fat % calculator
US Navy method from waist, neck, hip, and height (no scale needed)
Running pace calculator
Pace per km and per mile from total time + distance, with 5K/10K/half/marathon presets