TDEE in one sentence
TDEE — Total Daily Energy Expenditure — is the total number of calories your body burns in a 24-hour day, from keeping your heart beating to digesting lunch to your evening workout.
It's the single most useful number in nutrition: eat below it and you lose weight, eat above it and you gain, eat at it and you maintain. Every diet that works, works by manipulating intake relative to TDEE — whether it advertises that or not.
The four components of TDEE
BMR (Basal Metabolic Rate) — 60–70% of the total for most people. The energy cost of simply being alive: organ function, cell turnover, temperature regulation.
NEAT (Non-Exercise Activity Thermogenesis) — 10–25%, and the most variable component between individuals. Walking to the car, fidgeting, standing, housework — everything that isn't sleep, food or formal exercise.
TEF (Thermic Effect of Food) — roughly 10%. Digesting and processing food costs energy, with protein costing the most by far.
EAT (Exercise Activity Thermogenesis) — typically just 5–15%. Deliberate workouts, which are a smaller slice than most people assume.
How TDEE is calculated
Calculators estimate your BMR with a validated equation — usually Mifflin-St Jeor — then multiply by an activity factor between 1.2 (sedentary) and 1.9 (extremely active) that bundles NEAT, TEF and exercise together.
The result is an estimate with a real-world error band of roughly ±10%. The fix is empirical: eat at your calculated TDEE for two to three weeks, watch the scale trend, and adjust by 100–200 kcal until your weight holds steady.
Put it into practice: run your own numbers with the related calculator — free, instant, and nothing leaves your browser.
Frequently asked questions
Is TDEE the same as maintenance calories?
Yes — they describe the same number from two angles. TDEE is what you burn; maintenance calories are what you'd eat to match it.
Why does my TDEE differ between calculators?
Different sites use different BMR equations and activity-factor definitions. Differences of 100–200 kcal are normal and within the error band of every method.
Does TDEE change over time?
Constantly. It falls as you lose weight (a smaller body costs less to run), rises with muscle gain, and shifts with activity. Recalculate after every 5 kg of weight change.
More guides
- What Is BMR?
- Mifflin-St Jeor Calculator
- Harris-Benedict Calculator
- Katch-McArdle Calculator
- BMR vs TDEE: What's the Difference?
- What Are MET Values?
- What Is NEAT?
- The Thermic Effect of Food
- Activity Multipliers Explained
- What Is a Calorie?
- Metabolic Adaptation Explained
- The Calorie Deficit, Explained
- 500-Calorie Deficit
- 1,000-Calorie Deficit
- 300-Calorie Deficit
- How Many Calories to Lose 1 Pound a Week
- How Many Calories to Lose 2 Pounds a Week
- Reverse Dieting
- Maintenance Phase
- Calorie Cycling
- How Accurate Are TDEE Calculators?
- Not Losing Weight in a Calorie Deficit? 7 Real Reasons
- Is 1,200 Calories a Day Safe?
- Should You Eat Back Exercise Calories?
- How Long Does Metabolic Adaptation Last?
- Do You Burn Fewer Calories as You Lose Weight?
- Why Your Maintenance Calories Keep Changing
- Calorie Cycling vs Flat Deficit
- How to Avoid Muscle Loss on GLP-1 Medications
Sources
- Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990. [link]
- Pontzer H, Yamada Y, Sagayama H, et al. Daily energy expenditure through the human life course. Science. 2021. [link]
- Levine JA. Non-exercise activity thermogenesis (NEAT). Best Pract Res Clin Endocrinol Metab. 2002. [link]