TDEE, or total daily energy expenditure, is the total amount of energy you expend every 24 hours, expressed in calories.

There are four main components of TDEE:

1. Basal metabolic rate (BMR): BMR is the number of calories your body burns performing basic vital functions, such as breathing, pumping blood around your body, and maintaining brain function. It accounts for around 70% of TDEE.

2. Thermic effect of food (TEF): TEF is the number of calories you burn digesting food. On average, TEF accounts for around 10% of your TDEE, though this can vary depending on the types of food you eat. For instance, protein has a TEF of ~20-to-30%, carbs have a TEF of ~5-to-10%, and fat has a TEF of ~0-to-3%.

3. Exercise activity thermogenesis(EAT): EAT is the number of calories you burn doing formal exercise. For most people, EAT contributes approximately 5% to TDEE.

4. Non-exercise activity thermogenesis (NEAT): NEAT is the number of calories you burn from any physical activity that isn’t formal exercise (the calories you burn going about daily activities, basically). It accounts for around 15% of TDEE for most people.

People primarily use the information provided by a TDEE calculator to lose weight, gain muscle, or maintain their physique.They do this by manipulating their calorie intake based on the following three premises:

Eating more than your TDEE causes weight gain: If you consistently eat more than your TDEE, you’ll gain weight both in the form of body fat and lean body mass (primarily muscle). To gain muscle while accumulating as little fat as possible, aim to eat 5-to-10% above your TDEE.

Eating less than your TDEE drives fat loss: You’ll lose weight if you consistently eat fewer calories than your TDEE. Provided you eat adequate protein and lift weights, most of the weight you lose will be fat. To lose fat quickly and healthily, eat 20-to-25% fewer calories than your TDEE.

Matching your caloric intake to your TDEE aids weight maintenance: Aligning your daily calorie intake with your energy expenditure allows you to maintain your weight. Maintaining your weight is a good option for those who have reached their goal physique and no longer want to bulk or cut