Weight Loss Calorie Calculator

Calculator Inputs

• Mifflin–St Jeor BMR (default):
  BMR = 10·weight(kg) + 6.25·height(cm) − 5·age + s, where s = +5 for men and s = −161 for women.
• Katch–McArdle BMR (if body fat % is given):
  Lean body mass LBM = weight · (1 − bodyfat/100), then BMR = 370 + 21.6 · LBM(kg).
• TDEE: TDEE = BMR × activity_multiplier.
• Deficit from loss rate (approx):
  daily_deficit = (7700 × kg_per_week) / 7, then goal_calories = TDEE − daily_deficit.
• Macros: Protein and carbs use 4 kcal/g, fat uses 9 kcal/g.

1. Pick units, then enter age, height, and weight.
2. Select activity level that matches most weeks.
3. Optionally add body fat % for lean-mass estimating.
4. Choose your weekly loss rate, then set macro preferences.
5. Press Calculate to view calories and macro targets.
6. Use scenario table to compare different deficit levels.
7. Download CSV or PDF for your records and planning.

1) What does TDEE mean?

TDEE is your estimated daily energy burn, including activity. It starts with BMR, then multiplies by an activity factor to reflect movement and training.

2) Why are there two BMR methods?

Mifflin–St Jeor uses age, sex, height, and weight. If you know body fat percent, Katch–McArdle uses lean mass and may better match some physiques.

3) Is 7700 kcal per kilogram exact?

No. It is a common approximation for stored energy in body fat. Real-world loss varies with water, glycogen, adaptation, and adherence, so treat it as guidance.

4) What loss rate is considered reasonable?

Many people do well around 0.25–1.0 kg per week, depending on starting weight and lifestyle. Faster rates can be harder to sustain and may affect performance.

5) Why apply a calorie floor?

Very low intake can be difficult to maintain and may reduce nutrient adequacy. The floor is a practical safeguard, not a medical rule, and can be disabled.

6) How should I set protein?

During fat loss, higher protein can help preserve lean mass. A common range is 1.6–2.2 g per kilogram per day, adjusted to preferences and training.

7) Do macros need to be perfect every day?

No. Consistency over weeks matters more than daily precision. Use targets as averages, prioritize protein and fiber, and keep calories aligned with your goal.

8) Why might results differ from my tracker or wearable?

Wearables and trackers use their own models and can misestimate burn. Food logging also has error. Use this calculator as a baseline and adjust using trends.