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Calorie Calculator

Calculate your daily calorie needs using the Mifflin-St Jeor equation. Find calories for weight loss, maintenance, and muscle gain based on your activity level.

How Calories Are Calculated

This calculator uses the Mifflin-St Jeor equation, widely considered the most accurate formula for estimating calorie needs.

Mifflin-St Jeor Equation

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

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

Activity Multipliers

  • Sedentary (×1.2): Little to no exercise, desk job
  • Light (×1.375): Light exercise 1-3 days/week
  • Moderate (×1.55): Moderate exercise 3-5 days/week
  • Active (×1.725): Hard exercise 6-7 days/week
  • Very Active (×1.9): Very hard exercise, physical job

Calorie Goals

Weight Loss

A 500 calorie deficit per day leads to approximately 1 pound of weight loss per week. The calculator shows a moderate 500-calorie deficit.

Weight Gain

A 500 calorie surplus per day supports muscle gain when combined with resistance training. Larger surpluses may lead to excess fat gain.

Important Considerations

  • These are estimates—individual metabolism varies by 10-15%
  • Muscle mass increases calorie needs; body fat decreases them
  • As you lose weight, recalculate your needs every 10-15 pounds
  • Consult a healthcare provider before starting any diet program

Related Calculators

Frequently Asked Questions

What is TDEE?

Total Daily Energy Expenditure (TDEE) is the total number of calories you burn daily, including basal metabolism, physical activity, and digestion.

What is BMR?

Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest—just to maintain vital functions like breathing and circulation.

How accurate is the Mifflin-St Jeor equation?

The Mifflin-St Jeor equation is considered the most accurate formula for estimating BMR, within about 10% for most people. Individual results may vary.

How many calories to lose weight?

A deficit of 500 calories per day typically results in about 1 pound of weight loss per week. Never go below 1,200 calories (women) or 1,500 calories (men) without medical supervision.

Why does activity level matter?

Physical activity significantly increases calorie needs. A sedentary person and active athlete of the same weight can have TDEE differences of 1,000+ calories.