Calorie Deficit Calculator — Lose Weight Effectively
Calculate your calorie deficit for weight loss. Free online calorie deficit calculator — enter your TDEE and target weight loss per week.
How to Use
- Select your sex and enter your age, height, current weight and target weight.
- Set a target date — the date by which you want to reach your goal weight.
- The calculator instantly shows your required daily calorie deficit and a full intake plan.
Formula
BMR (Mifflin-St Jeor): Male = 10×W + 6.25×H − 5×A + 5 | Female = 10×W + 6.25×H − 5×A − 161
TDEE = BMR × Activity Multiplier (1.375 for lightly active)
Daily Deficit = (Weight to Lose × 7,700 kcal) ÷ Days to Goal
Daily Intake = TDEE − Daily Deficit
Example Calculation
Example: Female, 28 yrs, 165 cm, 75 kg → 65 kg in 90 days
| Parameter | Value |
|---|---|
| Sex | Female |
| Age | 28 years |
| Height | 165 cm |
| Current Weight | 75 kg |
| Target Weight | 65 kg |
| Days to Goal | 90 days |
| BMR | ~1,547 kcal/day |
| TDEE | ~2,127 kcal/day |
| Required Daily Deficit | ~856 kcal/day |
| Daily Intake Target | ~1,271 kcal/day |
Frequently Asked Questions
A calorie deficit occurs when you consume fewer calories than your body burns. This forces your body to use stored fat for energy, resulting in weight loss. 1 kg of fat ≈ 7,700 calories.
A safe rate is 0.5–1 kg per week (deficit of 500–1,000 kcal/day). Losing more than 1 kg/week increases muscle loss risk. Slow and steady is more sustainable.
If the required deficit exceeds 1,000 kcal/day, extend your target date. You should never eat below 1,200 kcal/day (women) or 1,500 kcal/day (men).
Exercise increases your TDEE, making it easier to maintain a deficit without eating too little. A combination of diet and exercise is most effective and preserves muscle mass.
Macronutrients are protein (4 kcal/g), carbohydrates (4 kcal/g), and fat (9 kcal/g). The intake plan suggests 30% protein, 40% carbs, 30% fat — a balanced distribution for weight loss.
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