What is TDEE and why does it matter?
TDEE is the energy your body spends across 24 hours. It has four parts: your basal metabolic rate (BMR, roughly 60-70 percent of the total), the thermic effect of food (about 10 percent), planned exercise, and all the non-exercise movement you do without thinking about it: walking, fidgeting, climbing stairs.
Eat at your TDEE and your weight stays put. Eat below it consistently and you lose weight. Eat above it and you gain. Every diet that works, works through this equation. The hard part has never been the math. It is doing the eating part consistently, which is exactly why most people quit calorie tracking within three weeks.
How is TDEE calculated? The Mifflin-St Jeor formula
This calculator uses the Mifflin-St Jeor equation, the formula a 2005 Academy of Nutrition and Dietetics systematic review (Frankenfield et al.) found to be the most accurate BMR estimate for the general population:
- Men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
- Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
BMR is then multiplied by an activity factor to get your TDEE:
| Activity level | Multiplier | Typical profile |
|---|---|---|
| Sedentary | 1.2 | Desk job, little or no exercise |
| Lightly active | 1.375 | 1-3 workouts per week |
| Moderately active | 1.55 | 3-5 workouts per week |
| Very active | 1.725 | 6-7 workouts per week |
| Extremely active | 1.9 | Physical job plus daily training |
Worked examples
Example 1: sedentary office worker. Male, 30 years, 80 kg, 180 cm. BMR = 10×80 + 6.25×180 − 5×30 + 5 = 1,780 kcal. TDEE = 1,780 × 1.2 ≈ 2,136 kcal. To lose about half a kilo per week he would target roughly 1,640-1,840 kcal per day.
Example 2: active woman. Female, 27 years, 62 kg, 166 cm, training 4 times a week. BMR = 10×62 + 6.25×166 − 5×27 − 161 = 1,361 kcal. TDEE = 1,361 × 1.55 ≈ 2,110 kcal. Maintenance sits right around 2,100; a gentle cut would be 1,700-1,800 kcal.
Example 3: very active man bulking. Male, 24 years, 72 kg, 178 cm, training 6 days a week. BMR = 10×72 + 6.25×178 − 5×24 + 5 = 1,718 kcal. TDEE = 1,718 × 1.725 ≈ 2,963 kcal. A lean bulk would target roughly 3,150-3,250 kcal with adequate protein.
How do you turn your TDEE into actual results?
Knowing your TDEE takes 30 seconds. Eating against it every day for months is the actual work, and it is where almost everyone fails. Manual logging is tedious, so people stop. Nobody checks in, so motivation dies. The number on this page is only a target; the result comes from staying close to it for weeks, not days, and from judging your weekly average rather than reacting to any single heavy meal.
That is the problem Calally was built for. You log meals by voice in about 3 seconds: say what you ate, the AI breaks down ingredients, calories, and macros, one tap to confirm. And a 24/7 AI coach with full access to your data answers the questions that actually matter: "How am I tracking against my TDEE this week?", "What should I eat tonight to stay in my deficit?" Low-friction logging keeps the data flowing, and the coach turns that data into a course correction before the week goes off track, not after.