Health and fitness calculators
The Health line has six calculators for body measurements and daily targets: BMI with the WHO categories, daily calories (TDEE) from the Mifflin-St Jeor equation, body fat by the US Navy tape method, heart-rate training zones, and protein and water needs. Results are estimates for healthy adults, not a medical diagnosis.
7 tools on the Health line
- BMI CalculatorBody mass index with the WHO category.
- Calorie CalculatorDaily energy needs (TDEE) by activity level.
- Body Fat CalculatorBody fat percentage from tape measurements.
- Cooking ConverterCups, tablespoons, millilitres for recipes. Also on the Converters line.
- Heart Rate CalculatorTraining zones from your max and resting rate.
- Protein CalculatorDaily protein target for your goal.
- Water Intake CalculatorHow much to drink per day, in litres and cups.
What each measurement tells you
BMI Calculator
A quick screening number from height and weight. 18.5 to 24.9 is the healthy range for adults. It cannot tell fat from muscle, so pair it with body fat.
Body Fat Calculator
Needs a tape measure: neck, waist and, for women, hips. More informative than BMI for muscular, very lean or older people.
Calorie Calculator
Maintenance calories for your age, size and activity, plus targets to lose about 0.5 kg or gain about 0.25 kg a week.
Protein Calculator
Daily grams for your goal, from 0.8 g per kg of body weight for general health up to about 2.4 g per kg while losing fat.
Heart Rate Calculator
Five training zones from your age and resting pulse, using the Tanaka maximum heart rate and the Karvonen heart-rate reserve method.
Water Intake Calculator
A daily target in litres and glasses, adjusted for exercise and hot weather.
Questions about health tools
How accurate are these health calculators?
They use published equations that are accurate on average but can be off for any one person. Mifflin-St Jeor estimates resting energy within about 10% for most adults, and tape-measure body fat is usually within 3 to 4 percentage points of lab methods. Treat results as a starting point and adjust from real progress.
Should I track BMI or body fat percentage?
Both, for different reasons. BMI only needs height and weight, so it is quick to track over time, but it cannot separate muscle from fat. Body fat percentage needs a tape measure and says more about health for athletes, older adults and anyone whose weight is mostly muscle.
Is anything I enter stored?
No. Every health calculator runs in your browser. Your height, weight and measurements are not sent to a server and are gone when you close the page.