Calorie Calculator
Calculate daily calorie needs for weight loss, maintenance, or gain. See personalized targets based on your age, gender, and activity level.
About Calorie Calculator
Understanding how many calories your body needs each day is a fundamental step for managing your weight and nutrition. This calculator gives you a personalized daily calorie target based on your physical stats and activity level, then shows how that number changes depending on your goal.
Personalized Calorie Targets
After entering your age, gender, height, weight, and activity level, you will see calorie targets for five different goals: losing one pound per week, losing half a pound per week, maintaining your current weight, gaining half a pound per week, and gaining one pound per week.
Visual Goal Comparison
A bar chart shows all five calorie targets side by side, making it easy to compare how your daily intake should change depending on your objective. The maintenance bar is highlighted so you can quickly see your baseline.
The Mifflin-St Jeor Equation
This calculator uses the Mifflin-St Jeor equation, one of the most validated formulas for estimating Basal Metabolic Rate. It was published in 1990 and has been shown to predict BMR within 10% for most healthy adults, making it a standard tool in clinical nutrition.
Metric and Imperial Units
Toggle between metric (cm/kg) and imperial (ft, in/lbs) units. The calculator converts everything internally, so you can use the measurement system you are most familiar with.
Privacy
All calculations happen in your browser. No personal data is transmitted to any server.
Frequently Asked Questions
How does this calorie calculator work?
This calculator uses the Mifflin-St Jeor equation to estimate your Basal Metabolic Rate (BMR), then applies an activity multiplier to determine your maintenance calories. From there, it adjusts up or down based on your selected goal to show the daily calorie intake needed for weight loss, maintenance, or weight gain.
How many calories should I eat to lose weight?
Weight loss requires eating fewer calories than you burn. A deficit of about 250 calories per day supports a loss of roughly half a pound per week, while a deficit of about 500 calories per day targets roughly one pound per week. This calculator shows both options so you can choose a sustainable pace.
Is eating too few calories dangerous?
Yes. Eating well below your BMR for extended periods can slow your metabolism, cause nutrient deficiencies, and lead to muscle loss. Most health professionals recommend that women eat at least 1,200 calories per day and men eat at least 1,500 calories per day, though individual needs vary. Consult a healthcare provider before starting a very low-calorie diet.
Why do men and women have different calorie needs?
On average, men tend to have more muscle mass and larger body frames than women, both of which increase calorie requirements. The Mifflin-St Jeor equation accounts for this by using different constants for male and female calculations.
How often should I recalculate my calorie needs?
Recalculate every time your weight changes by 5 to 10 pounds, or if your activity level changes significantly. As you lose or gain weight, your body's calorie requirements shift, so updating your targets helps you continue making progress toward your goal.