Calorie Deficit for Weight Loss: A Complete Guide
Losing weight comes down to one simple principle: eat fewer calories than your body burns. But how many fewer? Here is how to calculate a safe and sustainable calorie deficit.
Try it: Calorie Deficit Calculator
Enter your TDEE and target deficit to see your daily, weekly, and monthly calorie targets.
Calorie Deficit Calculator
How Calorie Deficit Works
Calculate BMR
Using the Mifflin-St Jeor equation based on weight, height, age, and gender.
Multiply by Activity
Your TDEE = BMR × activity factor. This is your maintenance calories.
Set Your Deficit
Subtract 500 cal/day to lose ~1 lb/week. A sustainable rate for most people.
The Science
One pound of body fat contains approximately 3,500 calories. A daily deficit of 500 calories creates a weekly deficit of 3,500 calories, resulting in about 1 pound of weight loss per week. This is considered a safe and sustainable rate by most health organizations.
The full calculator includes goal timeline projection and safe-deficit range guidance.
Open the full health calculatorWhat Is a Calorie Deficit?
A calorie deficit means consuming fewer calories than your body needs to maintain its current weight. One pound of body fat equals approximately 3,500 calories. To lose 1 pound per week, you need a daily deficit of about 500 calories.
Daily Calories for Weight Loss = TDEE - Deficit
Example: TDEE of 2,200 - 500 deficit = 1,700 calories/day = ~1 lb/week loss
Calculate Your TDEE (Total Daily Energy Expenditure)
TDEE is the total number of calories your body burns per day, including exercise. It is calculated using the Mifflin-St Jeor equation:
Men: BMR = 10 x weight(kg) + 6.25 x height(cm) - 5 x age - 161
Women: BMR = 10 x weight(kg) + 6.25 x height(cm) - 5 x age + 5
Then: TDEE = BMR x Activity Multiplier
| Activity Level | Multiplier |
|---|---|
| Sedentary (little/no exercise) | 1.2 |
| Light (1-3 days/week) | 1.375 |
| Moderate (3-5 days/week) | 1.55 |
| Active (6-7 days/week) | 1.725 |
| Very Active (hard exercise daily) | 1.9 |
How Big Should Your Deficit Be?
| Deficit | Weekly Loss | Difficulty |
|---|---|---|
| 250 cal/day | 0.5 lb (0.2 kg) | Easy |
| 500 cal/day | 1 lb (0.45 kg) | Moderate (Recommended) |
| 750 cal/day | 1.5 lb (0.7 kg) | Challenging |
| 1,000 cal/day | 2 lb (0.9 kg) | Aggressive (Max) |
Most experts recommend a deficit of 500-750 calories per day. Going below 1,200 calories (women) or 1,500 calories (men) daily should be done under medical supervision.
Macro Breakdown in a Calorie Deficit
When cutting calories, maintaining adequate protein is crucial to preserve muscle mass:
- Protein: 0.7-1.0 grams per pound of body weight (30-35% of calories)
- Fat: 0.3-0.4 grams per pound (25-30% of calories)
- Carbs: Remaining calories (35-45%)
Key Takeaways
- Calculate your TDEE first, then subtract 500-750 calories
- Aim for 1-2 pounds per week for sustainable loss
- Keep protein high to preserve muscle
- Use our Calorie Deficit Calculator for a personalized plan with macros