What is TDEE?
Total daily energy expenditure is an estimate of the energy your body uses over a whole day. It includes basic functions at rest, movement around your home or workplace, planned exercise and the energy used to process food.
Your maintenance calorie intake is the amount that would roughly balance this expenditure over time. It changes as your body size, daily movement, training and other circumstances change. A calculator gives you a starting estimate, rather than measuring your metabolism.
How this calculator works
We estimate resting energy with the rounded revised Harris–Benedict equations used in Richie Kirwan’s Heracles nutrition course, then multiply by your chosen activity factor. The equation uses age, height, weight and a male or female coefficient. This input is for the equation, rather than a description of your gender identity; the estimate may be less applicable during gender-affirming hormone treatment.
Female equation: 447.6 + (9.2 × kg) + (3.1 × cm) − (4.3 × age)
Choosing an activity level
Think about your full day, including your job and walking, rather than counting gym visits alone. An office worker who trains several times each week may still fit the lightly active option.
| Activity | Factor |
|---|---|
| Mostly seated, little exercise | 1.2 |
| Mostly seated, some walking or training | 1.4 |
| Regular movement and training | 1.6 |
| Physical job or substantial daily training | 1.8 |
These are broad estimates of your total activity. Do not add a second allowance for calories shown on your exercise tracker.
Make the estimate useful
Observe your weight trend over a few weeks alongside hunger, energy and performance. Daily changes can reflect fluid, salt and food in your digestive system. Consistent measurements and weekly averages are more informative than a single reading.
Use the calorie deficit calculator to explore a modest reduction, or the macro calculator to translate a calorie target into protein, fat and carbohydrate. Neither a wearable nor an equation can predict your exact daily needs.
Questions about this calculator
Is TDEE the same as BMR?
No. BMR describes energy use at complete rest. TDEE includes the rest of your day. The resting energy estimate in this tool is multiplied by your activity factor to estimate TDEE.
Should I eat back exercise calories?
Your activity factor already includes exercise and daily movement. Adding tracker calories again can count the same activity twice.
Why can other calculators give different results?
Different equations and activity factors produce different estimates. Real energy expenditure also varies between people and from day to day.
Does a higher TDEE mean a faster metabolism?
Not necessarily. Body size and activity strongly influence energy use. This tool does not diagnose a slow or fast metabolism.
Method and sources
Nutrition principles adapted from Dr Richie Kirwan’s Heracles course, Optimizing Your Nutrition, Modules 1 and 3. Calculator implementation and explanations by Heracles.