Calorie Deficit Calculator

Achieve your weight loss goals with precision

Calculator

Your Results

Your BMI (Body Mass Index)

kg/m²
Underweight Normal Overweight Obese

Basal Metabolic Rate (BMR)

calories/day

Maintenance Calories

calories/day

Recommended Calorie Target

calories/day

Daily Calorie Deficit

calories/day

Projected Weight Loss

kg per week

Note: These calculations provide estimates based on validated formulas. Individual results may vary based on genetics, medical conditions, and other factors. Always consult healthcare professionals before starting any weight loss program.

Weight Loss Projection

Related Tools

Waist-to-Hip Ratio Calculator

Assess your body shape and health risks based on waist and hip measurements.

Use Tool

Weight Loss Timeline Predictor

Estimate how long it will take to reach your target weight.

Use Tool

Body Mass Index (BMI) Calculator

Quickly calculate your BMI to understand your weight category.

Use Tool

Calorie Deficit Calculator

Calculate the daily calorie deficit needed to lose weight safely.

Use Tool

Understanding Calorie Deficit

What is a Calorie Deficit?

A calorie deficit occurs when you consume fewer calories than your body expends. This forces your body to use stored fat as energy, resulting in weight loss. The fundamental principle of weight loss is based on this energy balance equation:

Weight Loss = Calories In < Calories Out

Creating a calorie deficit of 3,500 calories theoretically results in losing 1 pound (0.45 kg) of body fat. This can be achieved through reducing calorie intake, increasing physical activity, or ideally, a combination of both approaches.

How We Calculate Your Needs

Our calculator uses several scientifically validated formulas to determine your energy needs:

1. Basal Metabolic Rate (BMR)

We use the Mifflin-St Jeor equation, which is considered the most accurate for most people:

For men:

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

For women:

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

2. Total Daily Energy Expenditure (TDEE)

Your TDEE is calculated by multiplying your BMR by an activity factor:

TDEE = BMR × Activity Multiplier

  • • Sedentary (little or no exercise): 1.2
  • • Light activity (1-3 days/week): 1.375
  • • Moderate activity (3-5 days/week): 1.55
  • • Very active (6-7 days/week): 1.725
  • • Extra active (physical jobs or twice-daily training): 1.9

3. Calorie Deficit

Your recommended calorie target is calculated by subtracting your chosen deficit from your TDEE:

Calorie Target = TDEE - Deficit

  • • Mild deficit: 250 calories (approx. 0.25 kg or 0.5 lb per week)
  • • Moderate deficit: 500 calories (approx. 0.5 kg or 1 lb per week)
  • • Aggressive deficit: 1000 calories (approx. 1 kg or 2 lb per week)

Note: The calculator will never recommend daily intake below 1,200 calories for women and 1,500 calories for men, as lower intakes may not provide adequate nutrition without medical supervision.

Best Practices for Healthy Weight Loss

Balanced Nutrition

Focus on whole foods, adequate protein (1.6-2.2g/kg), complex carbs, healthy fats, and plenty of fiber.

Sustainable Approach

Aim for gradual weight loss of 0.5-1kg per week. Extreme deficits lead to muscle loss and metabolic adaptation.

Regular Exercise

Combine resistance training (2-3x/week) with cardio (150+ minutes/week) for optimal fat loss and muscle retention.

Track Your Progress

Monitor weight, measurements, and calories but focus on non-scale victories like energy and fitness improvements.

Adequate Sleep

Aim for 7-9 hours of quality sleep. Poor sleep increases hunger hormones and reduces fat loss.

Meal Planning

Prepare meals in advance to avoid impulsive high-calorie choices. Focus on portion control and nutrient density.

Safe Rate of Weight Loss

For most individuals, experts recommend a rate of 0.5-1 kg (1-2 pounds) per week for sustainable weight loss. This typically requires a moderate calorie deficit of 500-1000 calories per day below maintenance levels.

Important: If you have any medical conditions, are pregnant or breastfeeding, are under 18, or have a history of eating disorders, consult with a healthcare professional before starting any weight loss program.

Nutrition & Weight Loss Glossary

Basal Metabolic Rate (BMR)

The number of calories your body needs to maintain basic functions like breathing and cell production at complete rest.

Total Daily Energy Expenditure (TDEE)

The total number of calories you burn in a day, including your BMR plus additional calories for daily activities and exercise.

Calorie Deficit

Consuming fewer calories than your body expends, which forces it to use stored fat for energy, leading to weight loss.

Macronutrients

The three main nutrients that provide calories: protein (4 cal/g), carbohydrates (4 cal/g), and fats (9 cal/g).

Body Mass Index (BMI)

A measure that uses height and weight to estimate body fat and categorize weight status. Calculated as weight(kg)/height(m)².

Metabolic Adaptation

The process where your body adjusts to lower calorie intake by decreasing metabolic rate, making weight loss progressively more difficult.

Thermic Effect of Food (TEF)

Calories burned during digestion. Protein has the highest TEF (20-30%), followed by carbs (5-10%) and fats (0-3%).

Non-Exercise Activity Thermogenesis (NEAT)

Calories burned during everyday activities not considered formal exercise, like walking, fidgeting, and household chores.