Calorie Deficit Calculator
Calculate your daily calorie needs and find the optimal deficit for sustainable weight loss based on your body and activity level.
Biological Sex(for metabolic calculation)
Height
Activity Level
This calculator provides estimates. Actual caloric needs vary based on individual metabolism and other factors.
Understanding Calories and Weight Loss
How We Calculate Your Calories
This calculator uses the Mifflin-St Jeor equation, which is considered the most accurate formula for estimating Basal Metabolic Rate (BMR). Your Total Daily Energy Expenditure (TDEE) is then calculated by multiplying your BMR by an activity factor.
What is BMR?
Your Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest - just to keep your vital organs functioning, like breathing and pumping blood. This accounts for about 60-70% of your total daily calorie burn.
What is TDEE?
Your Total Daily Energy Expenditure (TDEE) includes your BMR plus all the additional calories you burn through daily activities and exercise. Eating at your TDEE maintains your current weight.
Creating a Calorie Deficit
To lose weight, you need to consume fewer calories than your TDEE. This creates a calorie deficit, forcing your body to use stored fat for energy. General guidelines:
- 250 calorie deficit: Lose ~0.5 lbs (0.2 kg) per week - very sustainable, minimal hunger
- 500 calorie deficit: Lose ~1 lb (0.45 kg) per week - good balance of speed and sustainability
- 750 calorie deficit: Lose ~1.5 lbs (0.7 kg) per week - faster but may cause more muscle loss
Important Considerations
- Never go below 1,200 calories (women) or 1,500 calories (men) without medical supervision
- Protein intake becomes more important in a deficit to preserve muscle mass
- As you lose weight, recalculate your needs - your TDEE will decrease
- Calculators provide estimates - your actual needs may vary based on metabolism, hormones, and other factors
When to seek professional support
Weight management can be difficult, and this estimate is not a diagnosis or a personalised plan. Speak with a qualified healthcare professional if you have a medical condition, take medicines, are pregnant or breastfeeding, have concerns about your relationship with food, or need individual support.