Calorie Calculator — Daily Calorie Intake
Calculate how many calories you need per day to maintain, lose, or gain weight using the Mifflin-St Jeor equation. See also BMI Calculator and TDEE Calculator.
How Daily Calorie Needs Are Calculated
Step 1: Your Details
Age
Gender
Weight
Height
Step 2: Basal Metabolic Rate (BMR)
Calories your body burns at rest
Men: (10 × kg) + (6.25 × cm) − (5 × age) + 5
Women: (10 × kg) + (6.25 × cm) − (5 × age) − 161
Step 3: Total Daily Energy Expenditure (TDEE)
Your daily calorie needs to maintain current weight
Lose Weight
TDEE − 500
Maintain
= TDEE
Gain Weight
TDEE + 500
How the Calorie Calculator Works
This calculator uses the Mifflin-St Jeor equation, which is considered the most accurate formula for estimating daily calorie needs by the American Dietetic Association. It first calculates your Basal Metabolic Rate (BMR) — the number of calories your body burns at complete rest to maintain basic functions like breathing, circulation, and cell production. Then it multiplies BMR by an activity factor to estimate your Total Daily Energy Expenditure (TDEE) — the total calories you burn in a day including physical activity.
Calorie Calculation Formula (Mifflin-St Jeor)
For Men:
For Women:
TDEE:
Example (25-year-old male, 70kg, 175cm, moderately active)
BMR = (10 × 70) + (6.25 × 175) − (5 × 25) + 5
BMR = 700 + 1093.75 − 125 + 5 = 1,673.75 cal/day
TDEE = 1,674 × 1.55 = 2,594 cal/day
Activity Level Multipliers
| Level | Multiplier | Description |
|---|---|---|
| Sedentary | 1.2 | Little or no exercise, desk job |
| Lightly Active | 1.375 | Light exercise 1-3 days/week |
| Moderately Active | 1.55 | Moderate exercise 3-5 days/week |
| Very Active | 1.725 | Hard exercise 6-7 days/week |
| Extra Active | 1.9 | Very hard exercise, physical job |
Weight Loss and Weight Gain
To lose weight, you need to create a calorie deficit — consuming fewer calories than your TDEE. A deficit of 500 calories per day results in approximately 0.5 kg (1 lb) of weight loss per week, since 1 kg of body fat contains roughly 7,700 calories. To gain weight, create a calorie surplus by eating more than your TDEE.
Important: The minimum recommended daily intake is approximately 1,500 calories for men and 1,200 calories for women. Going below these levels without medical supervision can lead to nutritional deficiencies and metabolic slowdown.
Understanding Macronutrients
Macronutrients provide the energy (calories) your body needs. Protein (4 cal/gram) builds and repairs muscle tissue — aim for 0.8-1.2g per kg of body weight. Carbohydrates (4 cal/gram) are the body's primary energy source — whole grains, fruits, and vegetables are preferred. Fat (9 cal/gram) supports hormone production and nutrient absorption — focus on unsaturated fats from nuts, avocados, and olive oil. This calculator suggests a balanced 30/40/30 split (protein/carbs/fat), but optimal ratios vary by individual goals.
Frequently Asked Questions
How accurate is this calorie calculator?
The Mifflin-St Jeor equation is accurate to within 10% for most people. Individual variation depends on genetics, body composition, hormones, and metabolic adaptation. Use the result as a starting point and adjust based on real-world results over 2-4 weeks.
What is the difference between BMR and TDEE?
BMR (Basal Metabolic Rate) is the calories burned at complete rest — just to keep your body alive. TDEE (Total Daily Energy Expenditure) includes BMR plus all physical activity. TDEE is always higher than BMR.
How many calories should I eat to lose weight?
A moderate deficit of 500 calories below your TDEE is recommended for sustainable weight loss of about 0.5 kg per week. Extreme deficits (over 1,000 cal) can cause muscle loss, nutritional deficiencies, and metabolic slowdown.
Why does the Mifflin-St Jeor equation differ for men and women?
Men typically have more lean muscle mass and less body fat than women at the same weight, which results in a higher metabolic rate. The +5 (men) vs -161 (women) constant accounts for this average difference in body composition.