How it is calculated
1) Basal metabolic rate (BMR) — what your body burns at complete rest:
Men: BMR = 10×kg + 6.25×cm − 5×age + 5 Women: BMR = 10×kg + 6.25×cm − 5×age − 1612) Total daily energy expenditure (TDEE) = BMR × activity factor:
| Activity | Factor |
|---|---|
| Sedentary (desk job, no exercise) | 1.2 |
| Light (1–3 days/week) | 1.375 |
| Moderate (3–5 days/week) | 1.55 |
| Very active (6–7 days/week) | 1.725 |
| Extra active (physical job + training) | 1.9 |
3) Your goal: a 500-calorie daily deficit is roughly half a kilogram (about 1 lb) of loss per week; a 250–500 surplus suits gradual gain.
Worked example
A 30-year-old man, 80 kg, 178 cm, moderately active: BMR = 800 + 1,112.5 − 150 + 5 = 1,767.5 kcal. TDEE = 1,767.5 × 1.55 ≈ 2,740 kcal to maintain, and about 2,240 kcal to lose half a kilogram a week.
Frequently asked questions
How many calories to lose 1 kg a week?
That needs a deficit of about 1,000 kcal a day, which is hard for most people. Aiming for 0.25–0.5 kg a week usually protects muscle and energy better.
Is it safe to go below 1,200 calories?
Going below roughly 1,200 kcal (women) or 1,500 kcal (men) is not advised without medical supervision, as nutrient needs become hard to meet.
Why am I not losing weight in a deficit?
Estimates are approximate and daily weight swings with water. Track the 2–3 week average and adjust by 100–200 kcal if needed.
Can I use it during pregnancy or breastfeeding?
No — needs change in pregnancy and lactation and should be set by a doctor or dietitian.
What is the difference between BMR and TDEE?
BMR is what you burn at complete rest; TDEE is everything you burn in a day including movement and exercise.