MyFitnessPal Calorie & Macro Calculator
Use this calculator to estimate your daily calorie needs and macronutrient breakdown based on your personal details, activity level, and fitness goals. This tool provides a starting point similar to the calculations you'd find in apps like MyFitnessPal, helping you track your nutrition more effectively.
Understanding Your Calorie and Macro Needs
MyFitnessPal and similar apps help you track your food intake against a daily calorie and macronutrient target. This calculator uses established formulas to provide you with a personalized estimate, giving you a solid foundation for your nutrition plan.
Basal Metabolic Rate (BMR)
Your Basal Metabolic Rate (BMR) is the number of calories your body burns at rest to maintain basic bodily functions like breathing, circulation, and cell production. It's the minimum energy required to keep you alive. This calculator uses the Mifflin-St Jeor equation, which is considered one of the most accurate for estimating BMR:
- 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
Total Daily Energy Expenditure (TDEE)
Your Total Daily Energy Expenditure (TDEE) is the total number of calories you burn in a day, including your BMR and the calories expended through physical activity. It's your BMR multiplied by an activity factor:
- Sedentary: BMR × 1.2 (little or no exercise)
- Lightly Active: BMR × 1.375 (light exercise/sports 1-3 days/week)
- Moderately Active: BMR × 1.55 (moderate exercise/sports 3-5 days/week)
- Very Active: BMR × 1.725 (hard exercise/sports 6-7 days/week)
- Extremely Active: BMR × 1.9 (very hard exercise/physical job)
Your TDEE is the number of calories you need to consume to maintain your current weight.
Setting Your Calorie Goal
To lose or gain weight, you need to create a calorie deficit or surplus relative to your TDEE. Generally, a deficit of 500 calories per day leads to approximately 0.5 kg (1 lb) of weight loss per week, as 1 kg of fat is roughly equivalent to 7,700 calories. This calculator adjusts your TDEE based on your chosen weight goal:
- Maintain Weight: TDEE
- Mild Weight Loss (0.25 kg/week): TDEE – 250 calories
- Moderate Weight Loss (0.5 kg/week): TDEE – 500 calories
- Extreme Weight Loss (1 kg/week): TDEE – 1000 calories
- Mild Weight Gain (0.25 kg/week): TDEE + 250 calories
- Moderate Weight Gain (0.5 kg/week): TDEE + 500 calories
- Extreme Weight Gain (1 kg/week): TDEE + 1000 calories
Note: Extreme weight loss/gain targets should be approached with caution and ideally under professional guidance.
Macronutrient Breakdown (Macros)
Beyond total calories, the distribution of your macronutrients (protein, carbohydrates, and fats) is crucial for body composition and overall health. A common starting point for a balanced diet is:
- Protein: 30% of total calories (4 calories per gram)
- Carbohydrates: 40% of total calories (4 calories per gram)
- Fats: 30% of total calories (9 calories per gram)
This calculator provides a suggested macro split based on these percentages. You can adjust these ratios based on your specific dietary preferences, training style, or advice from a nutritionist.
Example Calculation:
Let's consider a 30-year-old male, 175 cm tall, weighing 70 kg, who is moderately active and aims for moderate weight loss.
- BMR Calculation (Male): (10 × 70) + (6.25 × 175) – (5 × 30) + 5 = 700 + 1093.75 – 150 + 5 = 1648.75 calories
- TDEE Calculation (Moderately Active): 1648.75 × 1.55 = 2555.56 calories
- Calorie Goal (Moderate Weight Loss): 2555.56 – 500 = 2055.56 calories (approx. 2056 calories)
- Macro Breakdown (for 2056 calories):
- Protein: (2056 × 0.30) / 4 = 616.8 / 4 = 154.2 grams
- Carbohydrates: (2056 × 0.40) / 4 = 822.4 / 4 = 205.6 grams
- Fats: (2056 × 0.30) / 9 = 616.8 / 9 = 68.53 grams
This individual would aim for approximately 2056 calories per day, with about 154g protein, 206g carbs, and 69g fats.
Remember, these are estimates. Individual needs can vary based on genetics, body composition, and specific training demands. Use these numbers as a starting point and adjust based on your progress and how your body responds.
Your Estimated Daily Needs:
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- Estimated BMR: " + Math.round(bmr) + " calories/day "; resultsHtml += "
- Estimated TDEE: " + Math.round(tdee) + " calories/day "; resultsHtml += "
- Your Daily Calorie Goal: " + Math.round(calorieGoal) + " calories/day "; resultsHtml += "
Suggested Macronutrient Breakdown:
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- Carbohydrates: " + Math.round(carbGrams) + " grams (" + Math.round(carbCalories) + " calories) "; resultsHtml += "
- Fats: " + Math.round(fatGrams) + " grams (" + Math.round(fatCalories) + " calories) "; resultsHtml += "