Przejdź do treści
Liczbnik

Calorie deficit calculator

A calorie deficit is the difference between the energy you burn (TDEE) and the energy you take in from food. When you eat less than you burn, the body draws on fat reserves. The calculator works out your daily calorie target, the predicted weekly weight loss, the estimated time to reach your target body weight and whether the chosen deficit is in a safe range.

Reviewed byRedakcja Liczbnik
Calculator
Calorie deficit resultsDaily calorie target (kcal)1,700
Weight loss per week (kg)
0.45
Estimated days to goal
154
Estimated weeks to goal
22
Deficit rating
tak

How the calorie deficit calculator works

The calculator uses the following formulas: 1. Target calories = TDEE - Daily deficit 2. Kg lost per week = Daily deficit x 7 / 7700 (1 kg of fat = 7700 kcal) 3. Days to goal = |Current weight - Target weight| x 7700 / Daily deficit 4. Weeks to goal = Days to goal / 7 5. Safety rating: safe = deficit 300-1000 kcal/day; caution = above 1000; too small = below 300 The most effective approach combines a calorie deficit with strength training to preserve muscle mass.

Example: TDEE 2200 kcal, deficit 500 kcal, goal: 85 to 75 kg

Your TDEE is 2200 kcal/day. You apply a 500 kcal deficit, so you eat 1700 kcal daily. Weekly deficit = 500 x 7 = 3500 kcal which is about 0.45 kg of fat tissue. You have 10 kg to lose: 10 x 7700 / 500 = 154 days which is about 22 weeks (5.5 months). A 500 kcal deficit is in the safe range (300-1000 kcal).

Frequently asked questions

What is a calorie deficit?

A calorie deficit occurs when you consume fewer calories than your total daily energy expenditure (TDEE). The body makes up the missing energy from stored fat tissue.

How many calories of daily deficit are needed to lose weight?

A 500 kcal/day deficit is about 0.5 kg per week. A 1000 kcal/day deficit is about 1 kg per week — the safest maximum rate. Too large a deficit risks nutritional deficiencies and loss of muscle mass.

What is TDEE and how do I calculate it?

TDEE (Total Daily Energy Expenditure) is the total daily energy use including basal metabolic rate and physical activity. You can calculate it with a BMR/TDEE calculator or measure it by tracking weight and calories over several weeks.

How fast can you safely lose weight?

A safe rate is 0.5-1 kg per week. Faster rates raise the risk of muscle loss and the yo-yo effect. A long-term strategy with a moderate deficit is more effective than very restrictive diets.

Does a calorie deficit slow down metabolism?

Yes, a prolonged large deficit can slow metabolism (adaptive thermogenesis). The body adjusts to lower calorie intake. It helps to use diet breaks and gradually reduce the deficit as you lose weight.

How many calories are in 1 kg of fat tissue?

1 kg of pure fat tissue is about 7700 kcal. In practice losing 1 kg of body weight requires a deficit of about 7000-8000 kcal, since weight loss also includes glycogen and water.

Indicative result

Results are indicative and do not constitute medical or dietary advice. Drastic calorie restriction can be dangerous to health. This is not medical advice — consult a doctor or dietitian before a major change in diet.
  • BMI calculator

    Calculate BMI (body mass index) using the WHO formula. Check whether you are underweight, normal, overweight or obese. Free BMI calculator.

    Health
See all