Calorie Deficit Calculator
Free online calorie deficit/surplus calculator. Input your Basal Metabolic Rate (BMR), daily activity expenditure, and dietary intake to automatically calculate your daily calorie balance. The tool displays expected weekly weight loss or gain rate and provides science-based dietary adjustment recommendations. All data is processed locally without uploading to any server.
Calorie Balance Calculator
Enter the following three key parameters to calculate your daily calorie deficit or surplus.
BMR (Basal Metabolic Rate) Estimator
Estimate your basal metabolic rate using the Mifflin-St Jeor equation. If you don't know your BMR, you can quickly estimate it here.
Frequently Asked Questions
A calorie deficit occurs when the total calories you burn daily exceeds the calories you consume. When your body is in a deficit state, it taps into stored fat to make up the energy gap, thereby achieving weight loss. Approximately 7,700 kcal of calorie deficit equals about 1 kg of body fat loss. Generally, a daily deficit of 300-500 kcal is recommended, resulting in weekly weight loss of 0.3-0.5 kg.
Theoretically yes, but excessive deficits (>1,000 kcal/day) come with side effects: decreased metabolism, muscle loss, fatigue, nutritional deficiencies, and increased risk of binge eating. A moderate deficit of 500-750 kcal is recommended, along with adequate protein intake and strength training, to maximize muscle retention while losing fat.
BMR (Basal Metabolic Rate) is the minimum calories your body needs at rest to maintain basic life functions like heartbeat, breathing, and body temperature. It accounts for 60-75% of total calorie expenditure. BMR is influenced by age, gender, weight, and muscle mass. Increasing muscle mass can raise BMR, helping with long-term weight maintenance.