Every calorie target starts with an estimate of how much energy your body uses. That estimate has two parts: your basal metabolic rate (BMR) and your total daily energy expenditure (TDEE).
BMR: the cost of staying alive
BMR is the energy needed to keep your heart beating, lungs breathing and cells functioning at complete rest. Mealify uses the Mifflin-St Jeor equation, one of the most accurate formulas for the general population:
- Men: (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5
- Women: (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161
TDEE: everything else added on
Your TDEE multiplies BMR by an activity factor that accounts for exercise, digestion (the thermic effect of food) and NEAT — non-exercise movement like walking, fidgeting and housework. Typical multipliers range from 1.2 for desk-bound days to 1.9 for very physical jobs plus hard training.
Why formulas are only a starting point
Equations can be off by 10-15% for any individual. That's why Mealify's adaptive engine compares what you actually eat with how your weight actually changes. Since 1kg of body fat stores roughly 7,700 kcal, a few weeks of honest logging lets Mealify calculate your real maintenance: if you averaged 2,300 kcal a day for 28 days and lost 1kg, your true TDEE is around 2,575 kcal.
Setting your target
- Fat loss: TDEE minus 300-500 kcal (about 0.5-1% body weight per week).
- Maintenance: eat at TDEE and focus on food quality.
- Muscle gain: TDEE plus 200-300 kcal.
Log consistently for 2-3 weeks and your dashboard will start showing your learned TDEE alongside the formula estimate.