Weight Loss Macro Calculator
Use this calculator to estimate your daily calorie needs and macronutrient breakdown (protein, fat, carbohydrates) for effective weight loss. Understanding your macros can help you achieve your goals by ensuring you get adequate nutrition while maintaining a calorie deficit.
lbs
kg
inches
cm
Sedentary (little or no exercise)
Lightly Active (light exercise/sports 1-3 days/week)
Moderately Active (moderate exercise/sports 3-5 days/week)
Very Active (hard exercise/sports 6-7 days a week)
Extremely Active (very hard exercise/physical job/training twice a day)
0.5 lbs per week
1.0 lbs per week
1.5 lbs per week
2.0 lbs per week
Understanding Your Macros for Weight Loss
Macronutrients, or "macros," are the three main components of food that your body needs in large amounts for energy and bodily functions: protein, fats, and carbohydrates. For weight loss, managing your intake of these macros, alongside a calorie deficit, is crucial.
Why Macros Matter for Weight Loss:
- Protein: Essential for building and repairing tissues, including muscle. A higher protein intake during weight loss helps preserve lean muscle mass, increases satiety (feeling full), and has a higher thermic effect (burns more calories during digestion).
- Fats: Crucial for hormone production, nutrient absorption, and overall health. Healthy fats provide sustained energy and contribute to satiety. However, fats are calorie-dense, so moderation is key.
- Carbohydrates: Your body's primary source of energy. Complex carbohydrates (like whole grains, fruits, and vegetables) provide fiber and sustained energy, while simple carbs (sugars) offer quick energy but can lead to energy crashes.
How the Calculator Works:
This calculator uses a multi-step process to determine your personalized macro recommendations:
- Basal Metabolic Rate (BMR): First, it estimates your BMR using the Mifflin-St Jeor equation, which calculates the calories your body burns at rest to maintain basic bodily functions.
- Total Daily Energy Expenditure (TDEE): Your BMR is then multiplied by an activity factor to estimate your TDEE, which is the total number of calories you burn in a day, including exercise and daily activities. This is your "maintenance" calorie level.
- Calorie Deficit: To lose weight, you need to consume fewer calories than your TDEE. The calculator applies a calorie deficit based on your chosen weekly weight loss goal (e.g., a 500-calorie daily deficit for 1 lb/week loss).
- Macro Distribution: Finally, the calculator distributes the remaining calories into protein, fats, and carbohydrates based on common recommendations for weight loss:
- Protein: Typically set at a higher level (e.g., 1 gram per pound of body weight) to support muscle preservation and satiety.
- Fats: Usually set as a percentage of total calories (e.g., 20-30%) to ensure essential fatty acid intake and hormonal health.
- Carbohydrates: The remaining calories are allocated to carbohydrates to fuel your activities and provide energy.
Example Calculation:
Let's consider a 30-year-old moderately active male, 5'10" (70 inches) tall, weighing 180 lbs, aiming to lose 1 lb per week.
- Inputs: Male, 30 years, 180 lbs, 70 inches, Moderately Active (1.55), 1 lb/week loss.
- BMR Calculation: (10 * 81.65 kg) + (6.25 * 177.8 cm) – (5 * 30) + 5 = 1798 calories
- TDEE Calculation: 1798 * 1.55 = 2787 calories (maintenance)
- Target Calories for Weight Loss: 2787 – (1 lb * 500) = 2287 calories
- Macro Distribution (approximate):
- Protein: 180g (720 calories)
- Fat: ~64g (576 calories)
- Carbohydrates: ~247g (988 calories)
(Note: These are example numbers and may vary slightly due to rounding in the actual calculator logic.)
Important Considerations:
- This calculator provides estimates. Individual needs can vary based on genetics, body composition, and specific training goals.
- Focus on nutrient-dense whole foods to meet your macro targets.
- Consistency is key. Track your intake and adjust your macros as your weight changes or if your progress stalls.
- Consult with a healthcare professional or registered dietitian before making significant dietary changes, especially if you have underlying health conditions.
Your Estimated Daily Macros for Weight Loss:
'; resultsHtml += 'Estimated Maintenance Calories (TDEE): ' + Math.round(tdee) + ' calories'; resultsHtml += 'Target Calories for Weight Loss: ' + Math.round(targetCalories) + ' calories'; resultsHtml += '- ';
resultsHtml += '
- Protein: ' + Math.round(proteinGrams) + 'g (' + Math.round(proteinCalories) + ' calories) '; resultsHtml += '
- Fat: ' + Math.round(fatGrams) + 'g (' + Math.round(fatCalories) + ' calories) '; resultsHtml += '
- Carbohydrates: ' + Math.round(carbGrams) + 'g (' + Math.round(carbCalories) + ' calories) '; resultsHtml += '