HomeAll ToolsAboutBlog
Nutrition

Calorie Deficit Calculator

Enter your TDEE and target fat loss rate to get your exact daily calorie intake goal — no crash dieting, just math.

Calorie Deficit Calculator

3,500 kcal = ~1 lb fat

Rate Units
—
Daily Calorie Target

One kilogram of body fat contains roughly 7,700 calories. To lose 0.5 kg per week, you need a daily deficit of ~550 kcal. This calculator converts your fat loss target into a precise daily calorie intake from your TDEE.

Formula: Daily intake = TDEE - (target kg/week × 7,700 / 7)

Calorie Deficit Rate Reference Table

Weekly LossDaily DeficitRiskBest For
0.25 kg / 0.5 lbs~275 kcal/dayVery LowMuscle preservation, beginners
0.5 kg / 1.1 lbs~550 kcal/dayLowMost people, sustainable cut
0.75 kg / 1.65 lbs~825 kcal/dayModerateExperienced, higher body fat
1.0 kg / 2.2 lbs~1,100 kcal/dayHighShort-term only, contest prep

Choosing the Right Deficit Size

A calorie deficit is the fundamental requirement for fat loss: you must consume fewer calories than your body burns (TDEE) to force it to draw on stored body fat for energy. The size of the deficit determines the rate of fat loss — and the risk of muscle loss. One kilogram of body fat stores approximately 7,700 kcal; one pound stores approximately 3,500 kcal. A daily deficit of 550 kcal therefore produces approximately 0.5 kg (1.1 lbs) per week of fat loss on average. For most strength athletes and gym-goers, a deficit of 300–500 kcal/day (0.3–0.5 kg or 0.7–1.1 lbs/week) strikes the best balance: meaningful fat loss while minimising muscle catabolism — particularly when paired with 2.0+ g/kg/day protein and continued resistance training. Aggressive deficits (1,000+ kcal/day) may accelerate scale weight loss but significantly increase the proportion of weight lost that is lean mass rather than fat, especially after the first few weeks.

Rule of thumb: If you are losing more than 1% of body weight per week for two consecutive weeks, the deficit is too aggressive. Slow, protein-rich cuts preserve significantly more muscle.

Frequently Asked Questions

For most people, a 300–500 kcal/day deficit is optimal. This produces 0.3–0.5 kg/week of fat loss while preserving most muscle mass. Deficits above 700–1000 kcal/day accelerate fat loss but significantly increase muscle catabolism, especially without very high protein intake and regular resistance training.
Yes, especially without adequate protein and resistance training. At higher deficits, the body increasingly turns to muscle protein for energy. Eating 2.0–2.4 g of protein per kg of body weight and continuing to lift heavy are the two best strategies to preserve lean mass during a cut.
As you lose weight, your TDEE drops (you're lighter and need fewer calories to maintain). This is called metabolic adaptation. After 4–6 weeks of a cut, recalculate your TDEE at your new weight and adjust your calorie target accordingly. Refeed days can also temporarily boost leptin and thyroid hormone to counteract adaptation.
This depends on how your TDEE was calculated. If your TDEE already includes your activity level (as this calculator assumes), you should not eat back exercise calories — they're already factored in. If you used a sedentary TDEE estimate, you may need to add back some (not all) calories from exercise.

Related Calculators

TDEE CalculatorFind your maintenance calories to plug into this calculator.Calculate TDEE → Macro CalculatorSplit your calorie target into protein, carbs, and fat.Calculate Macros → BMR CalculatorYour base metabolic rate before activity is added.Calculate → Protein Intake CalculatorSet daily protein goals to preserve muscle on a cut.Calculate →