Calorie Calculator - Free Online Daily Calorie Needs Calculator
Calculate your daily calorie needs for weight loss, maintenance, or muscle gain. Uses the Mifflin-St Jeor equation with personalized activity level adjustments.
About This Tool
Understanding your daily calorie needs is the foundation of any successful nutrition plan, whether your goal is to lose weight, maintain your current physique, or build muscle. Our free calorie calculator uses the Mifflin-St Jeor equation, which is considered one of the most accurate methods for estimating Basal Metabolic Rate (BMR) by leading nutrition researchers and the Academy of Nutrition and Dietetics.
The calculator takes into account your age, gender, weight, height, and physical activity level to determine your Total Daily Energy Expenditure (TDEE) -- the total number of calories your body burns in a day. From there, it adjusts your calorie target based on your specific goal. For weight loss, the calculator applies a moderate 500-calorie daily deficit, which typically translates to approximately one pound of fat loss per week. For weight gain, it adds 500 calories above maintenance to support lean mass development.
Beyond your primary target, the calculator also displays a comparison of different calorie scenarios so you can see how aggressive loss, moderate loss, maintenance, and moderate gain options compare side by side. This allows you to make informed decisions about the pace of your progress and choose a sustainable approach.
Keep in mind that calorie calculators provide estimates based on population averages. Individual metabolism can vary due to genetics, hormonal factors, body composition, and other variables. These numbers serve as an excellent starting point, but you may need to adjust your intake based on real-world results over time. Always consult your healthcare provider or a registered dietitian before making significant changes to your diet, especially if you have any medical conditions.
Key Features
- Uses the scientifically validated Mifflin-St Jeor equation for accurate BMR estimation
- Adjusts for five activity levels from sedentary to very active for personalized results
- Provides calorie targets for weight loss, maintenance, and weight gain goals
- Displays a comparison table of multiple calorie scenarios with projected weekly weight change
- Supports both imperial and metric unit systems
Frequently Asked Questions
How many calories should I eat per day to lose weight?
To lose weight safely, most health professionals recommend a deficit of 500 calories below your TDEE, which leads to roughly one pound of weight loss per week. Very low calorie diets (below 1,200 for women or 1,500 for men) should only be followed under medical supervision, as they can lead to nutrient deficiencies and metabolic slowdown.
What is the difference between BMR and TDEE?
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest just to maintain basic life functions like breathing, circulation, and cell production. TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor, representing the total calories you burn in a day including exercise, walking, and daily activities.
How accurate is the Mifflin-St Jeor equation?
The Mifflin-St Jeor equation is considered the most reliable predictive equation for estimating BMR in healthy adults, with studies showing it falls within 10% of measured values for most people. However, individual variation exists, so use the result as a starting point and adjust based on your actual results over 2-4 weeks.