Calorie Deficit Calculator
Calculate the exact daily calorie deficit required to reach your weight loss goal within your desired timeframe.
The Science of a Calorie Deficit
Weight loss is governed by thermodynamics. To lose weight, you must consume fewer calories than your body burns each day (your Total Daily Energy Expenditure, or TDEE). This state is known as a calorie deficit.
The 3,500 Calorie Rule
It takes a deficit of approximately 3,500 calories to lose one pound of body fat. Therefore, a daily deficit of 500 calories will result in roughly 1 pound of weight loss per week (500 * 7 = 3,500).
Worked Example
- Current Weight: 200 lbs
- Goal Weight: 180 lbs
- Weight to Lose: 20 lbs
- Timeline: 12 Weeks (84 Days)
- Total Calories to Burn: 20 * 3500 = 70,000
- Daily Deficit = 70,000 / 84 = 833 kcal/day.
- If TDEE is 2,500, Daily Target = 1,667 kcal.
Frequently Asked Questions
Is a 1,000 calorie deficit safe?
A 1,000 calorie daily deficit leads to 2 lbs of weight loss per week. While possible, it is aggressive and can lead to muscle loss and fatigue. A 500 calorie deficit is generally considered more sustainable.
Disclaimer: This calculator is for educational and informational purposes only. It is not a medical diagnosis or professional medical advice. The results provided should not be relied upon as a substitute for professional medical evaluation. Individual health needs vary greatly based on age, medical history, lifestyle, and other factors. Consult a qualified healthcare provider, doctor, or registered dietitian before making any health or medical decisions. If you are experiencing health concerns, seek immediate medical attention.