Weight Loss & Calorie Deficit Calculator
Calculate daily calorie deficit requirements and projected target completion date for safe, sustainable weight loss.
Body & Goal Inputs
Calorie Target & Timeline
About the Weight Loss & Calorie Deficit Calculator
Losing weight healthily requires maintaining a controlled, moderate energy deficit over time while fueling your body with sufficient macro and micronutrients. Creating an extreme deficit leads to muscle wasting and metabolic slowdown, while a steady 500 to 750 calorie daily deficit yields safe, sustainable fat loss.
Our Weight Loss Calculator estimates your total daily energy expenditure (TDEE) and calculates the exact daily calorie target needed to reach your dream weight safely.
How the Calculations Work
Energy balance dictates that approximately 3,500 calories equal 1 pound (or ~7,700 kcal per kg) of body fat.
Target Calories = TDEE - Daily Deficit | Weeks to Goal = (Weight Loss Needed * 7700) / (Deficit * 7)
Variables & Definitions
- TDEE: Total Daily Energy Expenditure based on basal metabolism and activity
- Deficit: Daily calorie gap (e.g. 500 kcal/day for 0.5 kg/week loss)
- Goal Date: Projected calendar date when target weight will be achieved
A person with a 2,400 kcal TDEE wanting to lose 10 kg targets a 500 kcal deficit. Daily target = 1,900 kcal. At ~0.45 kg loss per week, the 10 kg goal is reached in approximately 22 weeks.
Key Terms Explained
TDEE
Total Daily Energy Expenditure: the calories your body burns in 24 hours including workouts, digestion, and basal activity.
Calorie Deficit
Consuming fewer calories than your body burns, prompting it to mobilize stored adipose fat tissue for fuel.
Practical Tips & Pitfalls to Avoid
Aim for 0.5% to 1% body weight loss per week
Losing more than 1% of body weight weekly increases muscle catabolism and hormonal fatigue.
Prioritize dietary protein and resistance training
High protein intake (1.6 to 2.2g per kg of target weight) preserves lean muscle mass during a calorie deficit.
Frequently Asked Questions
A deficit of 300 to 500 calories per day (yielding ~0.5 to 1 lb of fat loss per week) is safe, sustainable, and protects your metabolic rate.
One kilogram of human adipose tissue stores approximately 7,700 kilocalories of metabolic energy.