Calorie Deficit Calculator
Calculate your daily calorie deficit to lose weight at your target rate. Find your TDEE and the exact calories needed per day.
YOUR TDEE
kcal/day
DAILY DEFICIT
kcal/day
TARGET INTAKE
kcal/day
WEIGHT LOSS
per week
What is Calorie Deficit Calculator?
A calorie deficit occurs when you consume fewer calories than your body burns in a day. Since one pound of fat equals approximately 3,500 calories, a sustained daily deficit of 500 calories leads to roughly one pound of fat loss per week. This calculator estimates your Total Daily Energy Expenditure (TDEE) using the Mifflin-St Jeor equation and then calculates the daily calorie target needed to hit your weight loss goal.
How to use
- 1 Enter your age, gender, height, and current weight.
- 2 Select your activity level to estimate your TDEE.
- 3 Enter your goal weight and the timeframe to reach it.
- 4 The calculator shows your TDEE, required daily deficit, and target calories per day.
- 5 It also flags if your target is too aggressive (below 1,200 kcal/day for women or 1,500 for men).
Formula
Example calculation
Female, 30 years, 165 cm, 75 kg, moderately active. BMR = 1,555 kcal. TDEE = 1,555 × 1.55 = 2,410 kcal. Goal: lose 5 kg in 10 weeks (70 days). Deficit = (5 × 7,700) ÷ 70 = 550 kcal/day. Target = 2,410 − 550 = 1,860 kcal/day.
Frequently asked questions
How big should my calorie deficit be?
A deficit of 300–500 kcal/day is considered moderate and sustainable, leading to 0.3–0.5 kg (0.6–1 lb) of fat loss per week. A deficit above 750–1,000 kcal/day is aggressive and may lead to muscle loss, fatigue, and nutrient deficiencies.
What is TDEE?
TDEE (Total Daily Energy Expenditure) is the total number of calories your body burns in a day, including basal metabolic rate, physical activity, and the thermic effect of food. It is the number you need to be below to lose fat.
Why shouldn't I go below 1,200 calories?
Very low calorie intakes make it extremely difficult to meet micronutrient needs, cause muscle loss, slow metabolism, and are unsustainable. 1,200 kcal/day for women and 1,500 for men are the commonly cited minimums for safety.
Can I lose weight without exercise?
Yes — weight loss is primarily driven by a calorie deficit, not exercise. Exercise makes the deficit easier to achieve and helps preserve muscle mass, but diet is the dominant factor for fat loss.
Why is my weight loss slower than expected?
Real weight loss includes water weight fluctuations, muscle gain if you exercise, and metabolic adaptation. The calculator gives a mathematical estimate. Actual results vary based on adherence, sleep, stress, and hormones.