What is a Calorie Calculator?

A calorie calculator helps you determine how many calories your body needs each day to maintain, lose, or gain weight. It uses your age, gender, height, weight, and activity level to calculate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE).

Key Concepts

BMR (Basal Metabolic Rate):

Calories burned at rest for basic bodily functions

60-75% of total daily calories

TDEE (Total Daily Energy Expenditure):

Total calories burned including activity and exercise

BMR × Activity Multiplier

Calorie Deficit/Surplus:

Difference between calories consumed and TDEE

-500 for weight loss, +500 for weight gain

BMR Calculation Formulas

Mifflin-St Jeor Equation:

Men: BMR = 10 × weight + 6.25 × height - 5 × age + 5

Women: BMR = 10 × weight + 6.25 × height - 5 × age - 161

Most accurate for most people

Harris-Benedict Equation:

Men: BMR = 88.362 + (13.397 × weight) + (4.799 × height) - (5.677 × age)

Women: BMR = 447.593 + (9.247 × weight) + (3.098 × height) - (4.330 × age)

Older formula, still widely used

Activity Level Multipliers

Activity Level	Multiplier	Description	Examples
Sedentary	1.2	Little or no exercise	Desk job, minimal movement
Lightly Active	1.375	Light exercise 1-3 days/week	Walking, light sports
Moderately Active	1.55	Moderate exercise 3-5 days/week	Running, cycling, swimming
Very Active	1.725	Hard exercise 6-7 days/week	Intense training, manual labor
Extremely Active	1.9	Very hard exercise, physical job	Athletes, construction workers

How to Use the Calorie Calculator

Enter your age, gender, height, and weight
Select your activity level
Choose your weight goal (maintain, lose, or gain)
Set your target rate of weight change
Click "Calculate" to see your calorie needs
View detailed breakdown of your energy expenditure

Example Calculations

Weight Loss Example:

30-year-old woman, 5'6", 150 lbs, moderately active

BMR = 1,447 calories

TDEE = 1,447 × 1.55 = 2,243 calories

Weight loss (0.5 lb/week) = 2,243 - 250 = 1,993 calories

Weight Gain Example:

25-year-old man, 6'0", 160 lbs, lightly active

BMR = 1,756 calories

TDEE = 1,756 × 1.375 = 2,415 calories

Weight gain (0.5 lb/week) = 2,415 + 250 = 2,665 calories

Weight Management Guidelines

Weight Loss:

0.5 lb/week: -250 calories/day
1 lb/week: -500 calories/day
1.5 lb/week: -750 calories/day
Don't go below 1,200 (women) or 1,500 (men)

Weight Maintenance:

Eat at your TDEE level
Monitor weight weekly
Adjust calories as needed
Focus on nutrient-dense foods

Weight Gain:

0.5 lb/week: +250 calories/day
1 lb/week: +500 calories/day
1.5 lb/week: +750 calories/day
Focus on lean muscle gain

Macronutrient Distribution

Protein:

10-35% of total calories

0.8-1.2g per pound of body weight

Essential for muscle building and repair

Carbohydrates:

45-65% of total calories

Primary energy source

Focus on complex carbs and fiber

Fat:

20-35% of total calories

Essential for hormone production

Focus on healthy fats

Factors Affecting Calorie Needs

Age: Metabolism slows with age
Gender: Men typically have higher BMR
Body Composition: Muscle burns more calories than fat
Activity Level: More activity = higher calorie needs
Hormones: Thyroid, stress, and other hormones affect metabolism
Genetics: Some people naturally have faster/slower metabolisms
Climate: Extreme temperatures can affect calorie needs
Pregnancy/Lactation: Increases calorie requirements

Tips for Accurate Calorie Tracking

Measurement Tips:

Weigh yourself at the same time daily
Use a food scale for accurate portions
Track everything you eat and drink
Be honest about your activity level
Adjust calories based on results

Lifestyle Tips:

Eat slowly and mindfully
Stay hydrated throughout the day
Get adequate sleep (7-9 hours)
Manage stress levels
Be consistent with your routine

Common Mistakes

Underestimating calorie intake
Overestimating activity level
Not accounting for cooking oils and condiments
Ignoring liquid calories
Setting unrealistic weight loss goals
Not adjusting calories as weight changes
Focusing only on calories, not nutrition
Not considering individual differences

When to Recalculate

After losing/gaining 10+ pounds
When changing activity levels
After significant lifestyle changes
If weight loss/gain plateaus
During pregnancy or breastfeeding
After major surgery or illness
When starting new medications

Applications

Weight Management: Plan calorie intake for goals
Fitness Planning: Fuel workouts appropriately
Nutrition Education: Understand energy balance
Medical Purposes: Support health conditions
Athletic Performance: Optimize nutrition for sports
Meal Planning: Structure daily eating patterns

Calorie Calculator

Personal Information

Results