Calculate Your Calorie Deficit
Enter your details for a personalized weight loss plan
Personal Information
Weight Goals
Goal: lose 20 lbs
Lifestyle & Preferences
This calculator uses the Mifflin-St Jeor equation, widely considered the most accurate BMR formula. Results are estimates and should not replace professional medical advice.
Ready to see your plan?
Fill in your details on the left and click "Calculate My Plan" to get your personalized results.
How to Calculate Your Calorie Deficit
A step-by-step guide using the Mifflin-St Jeor equation
Interactive Example
Drag the sliders to see how BMR, TDEE, and deficit change in real time:
Calculate Your Basal Metabolic Rate (BMR)
BMR is the number of calories your body burns at complete rest — just to keep you alive (breathing, circulation, cell production).
Mifflin-St Jeor Equation
Men: (10 × weightkg) + (6.25 × heightcm) - (5 × age) + 5
Women: (10 × weightkg) + (6.25 × heightcm) - (5 × age) - 161
Determine Your Total Daily Energy Expenditure (TDEE)
Multiply your BMR by an activity factor to account for how much you move throughout the day.
| Activity Level | Multiplier |
|---|---|
| Sedentary (desk job) | BMR × 1.2 |
| Lightly active (1-3 days/wk) | BMR × 1.375 |
| Moderately active (3-5 days/wk) | BMR × 1.55 |
| Active (6-7 days/wk) | BMR × 1.725 |
| Very active (athlete) | BMR × 1.9 |
Create Your Calorie Deficit
Subtract calories from your TDEE to create a deficit. A 500-calorie daily deficit equals approximately 1 pound of weight loss per week (3,500 calories = 1 pound of fat).
-250
cal/day
~0.5 lb/week
-500
cal/day
~1 lb/week
-750
cal/day
~1.5 lb/week
Set Your Macronutrient Targets
Divide your daily calories among protein, carbohydrates, and fat based on your goals and dietary preferences. Protein is especially important during a deficit to preserve muscle mass.
General guideline: Aim for 0.7-1.0g of protein per pound of body weight during a calorie deficit to minimize muscle loss. Our calculator automatically sets optimal ratios based on your dietary preference.