How to use this calculator
Enter your age, gender, current weight, and height. Choose your unit preference for weight (pounds or kilograms) and height (feet/inches or centimeters).
Select your activity level honestly. Most people overestimate their activity. If you have a desk job and exercise 3 times per week, choose "lightly active" or "moderately active" rather than "very active."
Choose your desired rate of weight loss and optionally enter a goal weight. The calculator will show your daily calorie target, estimated timeline, and a suggested macronutrient breakdown.
Understanding calorie deficits
Weight loss fundamentally requires a calorie deficit, meaning you consume fewer calories than your body burns. One pound of body fat contains approximately 3,500 calories, so a daily deficit of 500 calories produces about one pound of loss per week.
Your BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest just to keep you alive. Your TDEE (Total Daily Energy Expenditure) adds the calories burned through daily activity and exercise on top of your BMR.
The key is finding a deficit that produces results without being so aggressive that you lose muscle, feel miserable, or trigger excessive metabolic adaptation. For most people, a 500 to 750 calorie daily deficit hits the sweet spot.
Frequently asked questions
How many calories should I eat to lose weight?
Subtract 500 calories from your TDEE for approximately 1 pound of loss per week. Your TDEE depends on your BMR and activity level. This calculator determines both for you.
What is TDEE and why does it matter?
TDEE is your Total Daily Energy Expenditure, the total calories you burn per day. You must eat below this number to lose weight. It equals your BMR multiplied by an activity factor.
Is losing 2 pounds per week safe?
For most people, 1 to 2 pounds per week is the maximum safe rate. Faster loss increases risk of muscle loss and nutrient deficiencies. Those with more weight to lose can safely aim for the higher end.
What is the minimum safe calorie intake?
Women should generally not eat below 1,200 calories and men should not go below 1,500 calories per day without medical supervision. Below these levels, nutritional needs become very difficult to meet.
How accurate is this calculator?
The Mifflin-St Jeor formula is accurate to within about 10% for most people. Use it as a starting point, then adjust based on your actual weight trend over 2 to 3 weeks.