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Calorie Deficit Calculator

Calculate your TDEE and your optimal daily calorie intake for weight loss — based on your chosen pace. A calorie deficit of 300–500 kcal/day is the scientifically recommended range to lose fat without losing muscle mass.

Calculate Your Calorie Deficit
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What is the optimal calorie deficit?

The optimal deficit depends on how much fat you have to lose and how quickly you want to reach your goal. General guidelines:

  • **200–300 kcal/day (mild): * Suitable if you are close to your target weight, new to weight loss, or want to minimize muscle loss. Slow but sustainable.
  • **300–500 kcal/day (moderate): * The scientific standard. Gives 0.3–0.5 kg/week — fast enough to see results without compromising muscle mass.
  • **500–1000 kcal/day (aggressive): * Acceptable at high body fat percentage. Requires high protein intake (2.0–2.2 g/kg) and strength training to protect muscle.

Why does weight stall?

During prolonged calorie restriction, the body lowers its metabolism as a defense — adaptive thermogenesis. NEAT (unplanned movement) instinctively decreases and BMR drops slightly.

**Solution:** Take a *diet break* of 1–2 weeks at maintenance calories (your TDEE) every 8–12 weeks. This restores hormonal balance and makes the next diet phase more effective. It is not a failure — it is strategy.

The role of protein

The most important thing you can do to preserve muscle mass during calorie restriction is adequate protein intake. Research supports 1.6–2.2 g protein per kg body weight. Protein also has high satiety effect and high TEF (about 25–30% of protein calories go to digesting the protein) — making it extra valuable during a cut.

Frequently Asked Questions

How large a calorie deficit gives 1 kg weight loss per week?
1 kg of body fat contains about 7,700 kcal. To lose 1 kg/week requires a deficit of about 1,100 kcal/day — which is aggressive and carries a high risk of muscle mass loss. 0.5 kg/week (about 550 kcal/day deficit) is a more sustainable pace for most people.
What is the difference between calorie deficit and calorie restriction?
The terms are used synonymously. A calorie deficit means you eat fewer calories than you burn (below your TDEE), forcing the body to use stored energy — primarily fat, but also some muscle mass if the deficit is too large.
Can you eat too little and still not lose weight?
Yes — adaptive thermogenesis can slow weight loss with a prolonged calorie deficit. The body lowers its NEAT (unplanned movement) and BMR drops slightly as a defense against starvation. Solution: take a diet break of 1–2 weeks at maintenance intake (your TDEE) to reset your metabolism.
How much protein do you need during a calorie deficit?
1.6–2.2 g of protein per kg of body weight per day is recommended to preserve muscle mass during a calorie deficit. With more aggressive deficits or intense training, aim for the upper end of the range (2.0–2.2 g/kg). Protein also provides high satiety.
Is a calorie deficit dangerous?
A moderate calorie deficit (300–500 kcal/day) is not dangerous for healthy adults. A very large deficit (>1000 kcal/day) increases the risk of muscle mass loss, nutritional deficiency, fatigue and hormonal disruption. Consult healthcare providers with extreme restriction or if you have underlying conditions.

Ready to reach your weight loss goal?

You have the calorie goal. The next step is to log food against it and see how your body responds.

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