How daily calories are estimated
The calculator first works out your basal metabolic rate (BMR), the energy your body uses at rest, with the Mifflin-St Jeor equation:
- Men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
- Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
BMR is then multiplied by an activity factor to give total daily energy expenditure (TDEE):
| Activity level | Factor |
|---|---|
| Sedentary | 1.2 |
| Light (1–3 days a week) | 1.375 |
| Moderate (3–5 days a week) | 1.55 |
| Very active (6–7 days a week) | 1.725 |
| Extra active | 1.9 |
Losing or gaining weight
A daily deficit of about 500 kcal leads to roughly 0.5 kg (1 lb) of weight loss per week, because a kilogram of body fat stores about 7,700 kcal. A surplus of the same size supports a similar rate of gain. Slower changes are easier to keep up.
This calculator gives general information for healthy adults. It is not medical advice. Talk to a doctor or registered dietitian before making significant changes to your diet or exercise.