Total Daily Energy Expenditure is the number of calories you actually burn in a day, all sources included. Eat at your TDEE and weight holds steady; eat consistently below or above it and weight moves. Every calorie goal starts here.
The four components
NEAT surprises people. The difference between a sedentary desk worker and someone constantly on their feet can exceed 1,000 kcal per day — far more than a typical gym session contributes.
| Component | Share of TDEE | What it is |
|---|---|---|
| BMR | 60–70% | Keeping you alive at rest |
| NEAT | 15–30% | Non-exercise activity — walking, fidgeting, standing, chores |
| TEF | ~10% | Thermic effect of food: the energy cost of digestion |
| EAT | 5–15% | Deliberate exercise |
Setting a target
A kilogram of body fat stores roughly 7,700 kcal (about 3,500 kcal per pound). That ratio converts a daily deficit into a weekly rate of change.
| Goal | Daily adjustment | Expected weekly change |
|---|---|---|
| Aggressive fat loss | −1,000 kcal | −0.9 kg / −2 lb |
| Moderate fat loss | −500 kcal | −0.45 kg / −1 lb |
| Slow fat loss | −250 kcal | −0.23 kg / −0.5 lb |
| Maintenance | 0 | no change |
| Lean gain | +250 kcal | +0.23 kg / +0.5 lb |
| Faster gain | +500 kcal | +0.45 kg / +1 lb |
Deficits beyond about 25% of TDEE reliably cost muscle alongside fat and become hard to sustain. Slower is usually faster in the end.
Why the scale lies week to week
Daily weight swings of 1–2 kg are normal and almost entirely water: sodium intake, carbohydrate stored as glycogen (which binds roughly 3 g of water per gram), hormonal cycles, and the simple weight of undigested food.
Weigh yourself under the same conditions each time and compare weekly averages rather than individual readings. If the average has not moved in three weeks, adjust intake by 10% rather than guessing.
Adaptive thermogenesis
TDEE is not fixed. As you lose weight there is less of you to move and maintain, so TDEE falls — and it typically falls somewhat further than body size alone predicts, partly through reduced NEAT as energy availability drops.
The practical consequence: recalculate every 4–5 kg of change rather than holding one number for an entire cut.
Worked example
Using the values pre-loaded in the calculator above:
| Input | Value |
|---|---|
| Units | Metric (cm / kg) |
| Age (yrs) | 30 |
| Sex | Male |
| Height (cm or in) | 175 |
| Weight (kg or lb) | 75 |
| Activity level | Moderate — 3–5 days/week |
| Output | Value |
|---|---|
| TDEE (maintenance) | 2,633 kcal/day |
| BMR | 1,699 kcal/day |
| Activity multiplier | ×1.55 |
| Calories from activity | 934 |
Frequently asked questions
How is TDEE different from BMR?
BMR is what you burn at complete rest. TDEE is BMR plus everything else — movement, exercise and digestion. TDEE is always the larger number and is what you set calorie targets against.
Why is my weight not moving despite a deficit?
Most often the deficit is smaller than assumed — unlogged oils, drinks and portion drift add up fast. Water retention can also mask fat loss for weeks. Track carefully for two weeks before changing anything.
Should I eat back calories burned in exercise?
If you selected an activity multiplier that already reflects your training, exercise is counted. Adding it again double-counts. Fitness trackers also tend to overestimate exercise burn substantially.
How often should I recalculate?
Every 4–5 kg of weight change, or whenever your activity level shifts meaningfully.