Fitness and Health Calculators

Free health calculators for BMI, calories, body fat, BMR, ideal weight, and pregnancy. Understand your numbers with clear explanations.

• BMI CalculatorCalculate your body mass index from your height and weight, see the WHO category it falls into, and get the healthy weight range for your height — plus BMI Prime, the Ponderal Index, and how the number is read for children and teenagers.
• Calorie CalculatorEstimate how many calories you burn each day and what to eat to maintain, lose, or gain weight — choose from three BMR equations, six activity levels, and results in calories or kilojoules, with reference tables for common foods, exercise, and food energy.
• BMR CalculatorCalculate your basal metabolic rate — the calories your body uses at complete rest — with the Mifflin-St Jeor, revised Harris-Benedict, and Katch-McArdle equations, then see your daily need at every activity level in calories or kilojoules.
• Body Fat CalculatorEstimate your body fat percentage with the US Navy circumference method — just a tape measure — and see your fat mass, lean mass, the ideal body fat for your age, how far you are from it, and how a BMI-only estimate compares.
• Ideal Weight CalculatorCompare the four standard ideal body weight formulas for your height and sex, alongside the healthy weight range implied by BMI.
• Due Date CalculatorEstimate your due date from the first day of your last period, a conception date, an IVF transfer date, or a dated ultrasound — with today's gestational age, the trimester boundaries, and the early-, full- and post-term dates.