Calorie Deficit Calculator
Determine exact daily caloric restriction needed to reach target body weight milestones by a specific target date.
Understanding Caloric Deficits
Adipose tissue catabolism obeys thermodynamics: metabolizing roughly 1 kilogram of body fat requires creating an energy deficit of approximately 7,700 kilocalories.
Calculation Logic
Total Calorie Deficit = Weight to Lose (kg) × 7,700 kcal
Daily Calorie Target = Daily TDEE - (Total Deficit / Total Days)
Worked Example
Losing 10 kg over 12 weeks (84 days) with a 2,400 kcal maintenance requirement:
- Total energy deficit needed: 10 × 7,700 = 77,000 kcal
- Daily reduction: 77,000 / 84 = ~917 kcal/day
- Target intake: 2,400 - 917 = 1,483 kcal/day
Frequently Asked Questions
Is there a limit to how fast I can safely lose weight?
Medical guidelines recommend losing between 0.5% and 1% of total body weight per week to avoid gallstones, excessive muscle loss, and metabolic adaptation.
What happens if my required daily intake falls below 1,200 kcal?
Diets under 1,200 kcal/day (women) or 1,500 kcal/day (men) risk micronutrient deficiencies and should be supervised by a medical professional.
Why does weight loss plateau after several weeks?
Metabolic adaptation, reduced non-exercise activity thermogenesis (NEAT), and decreased body mass reduce daily baseline maintenance burn.
Should I adjust calories as weight drops?
Yes. Recalculate your TDEE every 3 to 4 kilograms of weight loss to sustain a constant rate of progress.
Calculate in three steps
- 1Enter your valuesUse the fields above and check the units shown beside each input.
- 2Run the calculationSelect Calculate to refresh the result with your latest values.
- 3Review or shareCompare the result, reset the form, print it, or share this page.