BMR and TDEE explained
BMR (basal metabolic rate) is the energy your body uses at complete rest to keep you alive: breathing, circulation, cell repair and so on. TDEE (total daily energy expenditure) adds the energy from movement, exercise and digesting food, so it is the number of calories that would keep your weight steady.
The equation used
This calculator uses the Mifflin-St Jeor equation, which is widely used and generally considered more accurate for modern populations than older formulas:
Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
TDEE = BMR × activity factor
The activity factors range from 1.2 for a mostly sedentary lifestyle to 1.9 for very hard daily training or a physically demanding job.
Example
A 35-year-old woman who weighs 65 kg and is 165 cm tall has a BMR of about 1,345 calories a day. With light activity (×1.375), her maintenance level is about 1,850 calories.
How to use the result
- Treat it as an estimate. Individual metabolism varies, and real needs can differ from the estimate by 10% or more.
- Watch your trend. Track your weight for two to three weeks while eating near the estimate. If it stays steady, that is your maintenance level.
- Changing weight gradually. A change of roughly 250 to 500 calories a day from maintenance is commonly used for slow, sustainable change. The often-quoted figure is that about 3,500 calories equals a pound of body weight, but that is only a rough guide.
- Eat enough. Very low calorie intakes should only be followed under medical supervision.
Who this is not for
The calculator is for healthy adults. It is not suitable for children, teenagers, pregnant or breastfeeding women, or people with medical conditions that affect metabolism. If you have a health condition or a history of disordered eating, speak with your doctor or a registered dietitian before changing how you eat. This page is general information and not medical advice.