Calorie Deficit Calculator
Find intake and weight loss from a calorie deficit.
A calorie deficit drives weight loss. Informational only — not a substitute for professional advice.
How the Math Works
The Calorie Deficit Calculator uses the formula weekly loss = deficit × 7 ÷ 7700 kcal/kg, where 'deficit' represents the daily calorie shortfall between intake and expenditure. Multiplying by 7 converts the daily deficit to a weekly total, while dividing by 7700 (the approximate energy content of 1 kilogram of body fat) translates this into kilograms of weight loss. This calculation assumes that all deficit comes from fat loss and provides an average estimate based on metabolic principles.
Practical Applications
To use this calculator, first determine your daily calorie deficit by subtracting your daily caloric intake from your total daily energy expenditure (TDEE). Input this deficit value into the formula to project weekly weight loss. For example, a 500-calorie daily deficit would yield approximately 0.38 kg (0.84 lbs) of weekly loss. Adjust your deficit to align with health guidelines (typically 500–1000 kcal/day for safe weight loss), and use the result to set realistic weekly goals.
Day-to-Day Use
This calculator empowers individuals to make data-driven decisions by linking dietary choices and physical activity to tangible weight outcomes. By tracking intake and understanding how small adjustments compound over time, users can create sustainable habits, such as replacing high-calorie snacks with healthier options or incorporating more movement into their routines. It transforms abstract concepts like 'losing weight' into a manageable process, fostering motivation through measurable progress and supporting long-term lifestyle changes.
Worked example
2,500 − 500 → 2,000 kcal, ~0.45 kg/week.
FAQ
Too aggressive?
Very large deficits are hard to sustain and can cost muscle.