Calorie Deficit Calculator
Calorie Plan
Daily Calorie Deficit Planning: TDEE, Target Calories, and Weight Loss Timeline
A calorie deficit calculator determines how many calories you need to consume daily to lose weight at your desired rate. A calorie deficit occurs when you consume fewer calories than your body burns through basic metabolic functions and physical activity. This calculator uses the scientifically validated Mifflin-St Jeor equation to calculate your maintenance calories, then determines the deficit needed to reach your goal weight within a healthy timeframe.
Understanding your calorie deficit is crucial for effective and sustainable weight loss. Whether you are trying to lose 5 kg or 20 kg, this calculator provides a personalized plan based on your age, gender, weight, height, and activity level. For comprehensive weight loss planning, combine calorie deficit strategies with realistic timelines and healthy lifestyle changes.
What is a Calorie Deficit?
A calorie deficit is the state where you consume fewer calories than your body burns for energy, forcing it to use stored fat for fuel. To create a deficit, you must eat below your TDEE (Total Daily Energy Expenditure). For example, if your TDEE is 2,500 calories and you eat 2,000 calories, you have a 500-calorie deficit. Since one kilogram of fat contains approximately 7,700 calories, a 500-calorie daily deficit results in about 0.5 kg weight loss per week.
Fat Loss Science: 7,700 Calories Per Kilogram Explained
Weight loss requires burning more calories than you consume. One kilogram of body fat contains approximately 7,700 calories. To lose 0.5 kg per week, you need a daily deficit of 550 calories (7,700 ÷ 14 days). For 1 kg weekly loss, you need a 1,100 calorie daily deficit. The calculator determines your Total Daily Energy Expenditure (TDEE) based on age, gender, weight, height, and activity level, then subtracts the appropriate deficit for your goal.
Slow vs Moderate vs Fast Weight Loss: 0.25-1 kg Per Week
Health experts recommend losing 0.5-1 kg per week for sustainable results. Faster weight loss often leads to muscle loss, metabolic slowdown, and difficulty maintaining results. A 0.25 kg weekly loss (slow) requires a 275-calorie daily deficit, 0.5 kg (moderate) needs 550 calories, 0.75 kg (fast) requires 825 calories, and 1 kg (very fast) needs 1,100 calories. Choose a rate that fits your lifestyle and does not leave you feeling deprived or exhausted.
Minimum Daily Calories: 1,200 for Women, 1,500 for Men
Never consume below 1,200 calories daily for women or 1,500 for men, even if calculations suggest lower. Eating too few calories triggers metabolic adaptation where your body slows metabolism to conserve energy, making weight loss harder. Very low calorie diets also risk nutrient deficiencies, muscle loss, fatigue, and hormonal imbalances. If your calculated target is below these minimums, extend your timeline or increase activity level instead.
For accurate daily calorie tracking, use our calorie calculator to determine your total daily energy expenditure based on your specific activity patterns and lifestyle.
Diet vs Exercise vs Combined Approach for Calorie Deficit
You can create a deficit through diet alone, exercise alone, or a combination (most effective). For a 500-calorie deficit: eat 250 fewer calories and burn 250 through exercise. This approach is more sustainable than extreme dietary restriction. Exercise also preserves muscle mass during weight loss, maintains metabolic rate, and provides health benefits beyond weight loss like improved cardiovascular fitness and mood.
Weekly Weigh-Ins and Deficit Adjustments Every 5 kg
Weigh yourself weekly at the same time (morning, after bathroom, before eating) and track the trend over 3-4 weeks. If you are not losing weight despite maintaining your deficit, your actual TDEE may be lower than calculated. Reduce calories by 100-200 or increase activity. If losing faster than planned, increase calories slightly to prevent muscle loss. Recalculate your deficit every 5 kg lost, as your maintenance calories decrease with weight loss.
Food Tracking Errors and Metabolic Adaptation Prevention
Underestimating food intake is the most common error - studies show people underreport by 20-50%. Use a food scale and tracking app for accuracy. Overestimating activity level is another pitfall; most people are sedentary or lightly active despite thinking otherwise. Avoid "eating back" all exercise calories, as calorie burn estimates are often inflated. Do not create excessive deficits hoping for faster results - this backfires through metabolic adaptation and muscle loss.
How Do I Calculate My Calorie Deficit?
To calculate your calorie deficit, first determine your TDEE (Total Daily Energy Expenditure) by calculating your BMR using the Mifflin-St Jeor equation and multiplying by your activity level. Then decide your weekly weight loss goal (0.5 kg = 550 calorie daily deficit, 1 kg = 1,100 calorie deficit). Subtract this deficit from your TDEE to get your target daily calories. Ensure your target stays above 1,200 calories for women or 1,500 for men to maintain metabolic health.