Energy needs calculator

Calculator · 2 min · free · no data stored

Estimate your resting basal metabolic rate (BMR) and your total 24-hour energy expenditure based on your age, height, weight and activity level.

Result preview

Example: Female, 35 y.o., 165 cm, 65 kg → ~1400 kcal (resting) / ~1900 kcal (active)

What this tool gives you

This tool estimates your resting energy expenditure and daily needs from your age, height, weight and activity level. It explains the difference between basal metabolism, total expenditure and intake matched to a goal.

You understand why severe restriction backfires, how physical activity and muscle mass change requirements, and what margins are realistic over several weeks.

The estimate is theoretical: it replaces neither a body-composition measurement nor an individual dietetic assessment.

Frequently asked questions

Is the estimate accurate?: It is a statistical approximation. Body composition, treatments and illness change real requirements.
Is it suitable in pregnancy or illness?: No. Those situations need an individual calculation in consultation.
How do I get a more precise measurement?: Through a body-composition analysis carried out at the practice.

Method and sources

The calculation uses the Mifflin-St Jeor equation (1990), recommended by the Academy of Nutrition and Dietetics as the most accurate predictive formula for healthy adults.

Female: (10 × weight) + (6.25 × height) − (5 × age) − 161
Male: (10 × weight) + (6.25 × height) − (5 × age) + 5

Total energy expenditure (TEE) applies an activity factor (PAL) between 1.2 and 1.725, based on FAO/WHO/UNU 2001. A range of ±7% reflects individual variability.

Sources: Mifflin MD et al., Am J Clin Nutr 1990;51:241-7; FAO/WHO/UNU, Human energy requirements, 2004; Academy of Nutrition and Dietetics, Evidence Analysis Library.

Clinical methodology: the calculation uses the resting-energy-expenditure equations applied in dietetic practice with standard activity factors, within conventioned practice in Luxembourg (CNS–ANDL convention). In consultation the estimate is compared with a body-composition analysis.

What's next?

These pointers are a starting point: the next steps are built with a professional, from your actual situation.

See all tools