Fitness & Health Calculators
Free, easy-to-use calculators to help you understand your body and reach your health goals. Check your BMI and body fat, find out how many calories you need, see how many you burn, and plan your workouts. Every calculator works in metric or imperial units and explains your result in plain language.
Weight & Body Composition
Calories & Energy
Activity & Performance
Pregnancy
- Due Date CalculatorEstimate your baby's delivery date
- Pregnancy CalculatorWeek-by-week pregnancy schedule and milestones
- Conception CalculatorEstimate your conception date and fertile window
See all pregnancy calculators.
Which calculator should I use?
Want to know if your weight is healthy? Start with the BMI Calculator, then use the Body Fat Calculator for a clearer picture, since BMI cannot tell muscle from fat. The Ideal Weight Calculator gives you a realistic target range.
Trying to lose or gain weight? The Calorie Calculator shows how much to eat each day for your goal. The Macro Calculator then splits those calories into protein, carbs and fat, and the Calories Burned Calculator shows how much your workouts add.
Training for a run or walk? Use the Pace Calculator to plan your speed and finishing time, and the Water Intake Calculator to stay hydrated.
How accurate are these calculators?
Our calculators use well-established, research-based formulas, such as the Mifflin-St Jeor equation for calorie needs, the U.S. Navy method for body fat and MET values from the Compendium of Physical Activities for calories burned. They give reliable estimates for most healthy adults, but everyone's body is different. Use the results as a helpful guide, track your progress over a few weeks, and speak with a doctor or registered dietitian before making big changes, especially if you have a health condition or are pregnant.