Health calculators

Free, science-based calculators for weight, nutrition and fitness. Each one explains its formula and sources.

• BMI CalculatorBody mass index for adults with WHO categories.
• Ideal WeightIdeal weight and healthy range for your height and sex.
• Calorie Deficit CalculatorHow many calories to eat and how many weeks it takes to reach your ideal weight.
• Waist-to-Height RatioA simple belly-fat check: keep your waist under half your height.
• Body Fat CalculatorEstimate your body fat percentage with a tape measure (U.S. Navy method).
• Macro CalculatorDaily calories and grams of protein, fat and carbs for your goal.
• Calories Burned CalculatorCalories burned walking, running, cycling, swimming and 25 other activities.
• Water Intake CalculatorHow much water to drink a day for your weight, activity and climate.
• BMI for KidsBMI-for-age for children and teens (WHO).