Calories & Nutrition

Losing, gaining or maintaining weight ultimately depends on daily energy balance: the energy the body uses at rest, movement during the day and calories eaten. This page helps you find the starting point, an estimate of your needs.

Which tool for which question?

• BMR and Daily Calorie Needs Calculator: Calculate your basal metabolic rate (BMR) with the Mifflin-St Jeor equation and your daily calorie needs from your activity level, plus daily calories for a weight loss or gain goal.
• Ideal Weight Calculator (Devine, Robinson, Miller, Hamwi): Estimate your ideal body weight from height and sex with four classic formulas (Devine, Robinson, Miller, Hamwi), their average and the BMI-based healthy weight range.
• Body Mass Index (BMI) Calculator: Calculate your body mass index (BMI) from weight and height, see your WHO class, the healthy weight range for your height and how much weight separates you from it.

How the calculation works

• Basal metabolic rate (BMR) is the daily energy the body uses at rest. The tool uses Mifflin-St Jeor, one of the most widely recommended estimating equations, with age, height, weight and sex.
• Daily calorie need = BMR × activity factor; for a weight goal some amount is subtracted from or added to this value.
• Body mass index = weight ÷ height², interpreted by the World Health Organization adult classes.
• Ideal weight is a reference weight estimated from height and sex with four classic formulas (Devine, Robinson, Miller, Hamwi).

Things to watch

• BMI does not distinguish muscle mass; it can mislead athletes.
• Ideal weight formulas were originally developed for clinical purposes and different formulas give different values; read the result as a range.
• Choosing a realistic activity level determines the result.

Results are estimates and do not replace medical advice, diagnosis or treatment; consult your doctor or dietitian for health decisions.