Enter your age, sex, height, weight, and activity level to get your estimated daily calorie needs. The Simple Calorie Intake Calculator uses the Mifflin-St Jeor equation to calculate your BMR and TDEE, showing how many calories you need to maintain, lose, or gain weight.
Daily Calorie Goal
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Basal Metabolic Rate (BMR)
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Maintenance Calories (TDEE)
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Suggested Protein
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Suggested Carbs
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Suggested Fat
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Most adults need between 1,600 and 3,000 calories per day, depending on age, sex, height, weight, and activity level. This calculator uses the Mifflin-St Jeor equation to give you a personalized estimate based on your details.
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest just to keep vital functions going — breathing, circulation, and cell production. The Mifflin-St Jeor formula calculates BMR as: 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5 for males (−161 for females).
TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor that accounts for how much you move each day. It represents the total calories you burn in 24 hours and is the baseline for setting any weight management goal.
A deficit of approximately 500 calories per day typically results in losing about 1 pound per week, since one pound of fat equals roughly 3,500 calories. Reducing more than 1,000 calories per day is generally not recommended without medical supervision, as it can lead to nutrient deficiencies.
Eating below your BMR means consuming fewer calories than your body needs to sustain basic functions at rest. This is generally not recommended for extended periods, as it can slow metabolism, cause muscle loss, and lead to nutritional deficiencies. Always consult a healthcare professional before adopting a very low-calorie diet.
The Mifflin-St Jeor equation is widely considered the most accurate for most people and is the formula used by this calculator. The Harris-Benedict equation is older and tends to slightly overestimate calorie needs. For individuals with a known body fat percentage, the Katch-McArdle formula can be even more precise.
Activity level multiplies your BMR by a factor ranging from about 1.2 (sedentary) to 1.9 (very active). This means a highly active person can need 50–60% more calories per day than someone with a desk job and no formal exercise — even if they are the same height, weight, and age.
Macronutrients — protein, carbohydrates, and fat — each provide calories: protein and carbs supply 4 kcal per gram, while fat supplies 9 kcal per gram. A common balanced split is 30% protein, 40% carbs, and 30% fat, but individual goals (muscle gain, fat loss, endurance) may call for different ratios.