Calorie Calculator

Complete Guide to Calories and Weight Management

Understanding how calories work is the foundation of successful weight management. Whether you want to lose fat, build muscle, or maintain your current weight, knowing your caloric needs is the first step toward achieving your fitness goals.

What is a Calorie?

A calorie is a unit of energy. Specifically, 1 calorie is the amount of energy needed to raise 1 gram of water by 1°C. When we talk about food calories, we actually mean kilocalories (kcal)—1,000 small calories. Your body uses calories from food to power everything from breathing and thinking to running and lifting weights.

Understanding TDEE (Total Daily Energy Expenditure)

Your TDEE represents the total calories you burn in 24 hours. It consists of four components:

BMR (60-75%)

Basal Metabolic Rate—calories burned at complete rest for vital functions like breathing and circulation. Use our BMR Calculator to find yours.

TEF (10%)

Thermic Effect of Food—energy used to digest, absorb, and process nutrients

TEA (5-15%)

Thermic Effect of Activity—calories from planned exercise

NEAT (15-30%)

Non-Exercise Activity Thermogenesis—energy from daily movements like walking, fidgeting, standing

Calorie Calculation Formula

Our calculator uses the Mifflin-St Jeor equation, the most accurate formula for estimating BMR:

For Men:

BMR = (10 × weight kg) + (6.25 × height cm) - (5 × age) + 5

For Women:

BMR = (10 × weight kg) + (6.25 × height cm) - (5 × age) - 161

Then:

TDEE = BMR × Activity Multiplier

Activity Level Multipliers

Activity Level	Multiplier	Description
Sedentary	1.2	Desk job, little to no exercise
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	Physical job + training 2x/day

Calorie Goals for Different Objectives

For Fat Loss (Cutting)

Moderate deficit: TDEE - 500 calories = ~0.5 kg (1 lb) loss per week
Aggressive deficit: TDEE - 750 calories = ~0.75 kg (1.5 lb) loss per week
Minimum intake: Never go below 1200 kcal (women) or 1500 kcal (men)
Protein priority: Keep protein high (1.6-2.2g/kg) to preserve muscle

For Muscle Gain (Bulking)

Lean bulk: TDEE + 200-300 calories for slow, clean gains
Standard bulk: TDEE + 500 calories for faster muscle growth
Protein needs: 1.6-2.2g/kg body weight for optimal muscle synthesis
Training emphasis: Progressive overload is essential to utilize the surplus

For Maintenance

Eat at your TDEE to maintain current weight
Focus on food quality and micronutrient intake
Good for body recomposition (gaining muscle while losing fat slowly)

Understanding Macronutrients

Macros are the three main nutrients that provide calories:

Protein (4 kcal/g)

Builds/repairs muscle, most satiating macro, highest TEF (20-30%)

Carbs (4 kcal/g)

Primary energy source, fuels workouts, stores as glycogen

Fats (9 kcal/g)

Hormone production, nutrient absorption, brain function

Frequently Asked Questions

How many calories should I eat to lose weight?

Create a deficit of 500-750 calories below your TDEE for sustainable weight loss of 0.5-0.75 kg (1-1.5 lbs) per week. For a 2000 calorie TDEE, aim for 1250-1500 calories daily.

Why am I not losing weight even in a calorie deficit?

Common reasons: underestimating portion sizes, not tracking liquid calories, overestimating activity level, or metabolic adaptation from extended dieting. Try tracking everything for a week, including cooking oils and condiments.

Do I need to count calories to lose weight?

Not necessarily, but it helps. You can lose weight through portion control, eliminating processed foods, or intermittent fasting. However, calorie counting provides precise data and faster progress.

Is 1200 calories too low?

For most adults, yes. 1200 calories is the minimum for women, 1500 for men. Going lower risks muscle loss, nutrient deficiencies, metabolic slowdown, and binge eating. It's better to create a smaller deficit and be patient.

How accurate are calorie calculators?

They're estimates with ±10-15% accuracy. Use your result as a starting point, track your weight for 2-4 weeks, then adjust by 100-200 calories based on actual results.

What's more important: calories or macros?

For weight change, total calories matter most. For body composition (muscle vs. fat), macros become important—especially protein. Aim for adequate protein first, then distribute remaining calories between carbs and fats based on preference.