WEIGHT LOSS/GAIN CALCULATOR
What is TDEE and why it matters?
TDEE stands for Total Daily Energy Expenditure and it is a measure of how much energy in Calories or kilocalories (kcal) you expend during your day and this is exactly what our TDEE calculator helps you estimate. There are three main things that affect it: physical activity, dietary-induced thermogenesis, and the climate you spend your day in. For women pregnancy is also a factor as it increases the energy cost of physical activities. Of the three, the most profound is the effect of physical activity - usually between 15 - 30% of TDEE
TDEE and losing weight
Knowing your TDEE is a great way to control your weight. Even estimating it with a tool like our total daily energy expenditure calculator, while not as precise as medically accurate procedures, is still much better than eyeballing, as many people do not have an accurate idea of how much energy they need, leading to a widespread obesity problem some people claim are of epidemic proportions, especially in the West. Understanding what factors influence energy expenditure - as explained above and elsewhere is also a good start, so if you are not yet asking yourself "how many calories should I eat a day?", you should!
Estimating Total Daily Energy Expenditure
To determine the TDEE one needs to estimate or know: the resting metabolic rate (includes basal and sleeping conditions and the cost of staying awake) the thermogenic influence of any food consumed during the day the energy expended during physical activity and post-activity recovery (physical work, sports training, etc.) The basal metabolic rate (BMR) is the minimum energy requirement to stay alive and awake. It is measured by the oxygen uptake under strict conditions, namely: no food consumed and no undue muscle exertion in the 12 hours preceding the measurement; the measurement is taken after 30-60 min of resting or laying quietly in a temperature neutral environment . Values measured this way are only slightly lower than the resting metabolic rate (RMR), which is measured under less strict conditions. You can use our Basal Metabolic Rate Calculator and our Resting Metabolic Rate Calculator to do these calculations, but if you are only interested in total daily energy expenditure, it is unneeded. Body surface area (BSA) and Body Mass Index (BMI) are sometimes used to estimate TDEE. Accurate measurement of BSA is a challenge, so usually estimations are used, based on studies, while BMI is mathematically defined, so no estimation is needed. In our software we use body mass, stature, gender, and age to predict resting daily energy expenditure (RDEE) and then combine that with the level of exercise you specify to arrive at an accurate total daily energy expenditure estimate  in Calories.