Macro Calculator
Calculate your daily macronutrient needs protein, carbohydrates, and fat based on your age, gender, height, weight, activity level, and fitness goal. Uses the Mifflin-St Jeor equation for BMR, considered the most accurate for the general population.
What Are Macronutrients?
Macronutrients are the three main nutrients your body needs in large amounts: protein, carbohydrates, and fat. Each plays a vital role in your health and fitness:
- Protein (4 kcal/g): Essential for muscle growth, repair, and recovery. Also helps keep you feeling full.
- Carbohydrates (4 kcal/g): Your body's primary source of energy. Carbs fuel workouts, brain function, and daily activities.
- Fat (9 kcal/g): Supports hormone production, vitamin absorption, and overall health. Healthy fats are essential for optimal body function.
How Does the Macro Calculator Work?
This calculator uses the Mifflin-St Jeor equation, which is recommended by the Academy of Nutrition and Dietetics as the most accurate BMR formula for the general population.
For Men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age(y) + 5
For Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age(y) − 161
In imperial units: weight in lbs × 4.536, height in inches × 15.88
TDEE (Total Daily Energy Expenditure) is calculated by multiplying your BMR by an activity factor based on your lifestyle.
- Sedentary: BMR × 1.2 (little or no exercise)
- Lightly Active: BMR × 1.375 (1-3 days/week)
- Moderately Active: BMR × 1.55 (3-5 days/week)
- Very Active: BMR × 1.725 (6-7 days/week)
- Extra Active: BMR × 1.9 (athlete/physical job)
For weight loss, a calorie deficit of 300-500 kcal per day is applied. For weight gain, a calorie surplus of 300-500 kcal per day is applied.
Macronutrient Split Recommendations
- Weight Loss: Higher protein (30-40%), moderate fat (20-30%), lower carbs (30-40%)
- Maintenance: Balanced split — protein 30%, carbs 40%, fat 30%
- Muscle Gain: High protein (25-35%), moderate fat (20-30%), higher carbs (40-55%)
Protein is calculated at 1.6-2.2 g per kg of body weight for active individuals (or 0.8-1.0 g per pound of body weight). This ensures adequate muscle protein synthesis and recovery.
❓ Macro Calculator FAQ
What are macronutrients?
Macronutrients are the three main nutrients your body needs in large amounts: protein, carbohydrates, and fat. Each provides energy (calories) and plays a specific role in your health, fitness, and body composition.
How is BMR calculated?
BMR (Basal Metabolic Rate) is calculated using the Mifflin-St Jeor equation. For men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age(y) + 5. For women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age(y) − 161.
What is TDEE?
TDEE (Total Daily Energy Expenditure) is the total number of calories you burn each day, including all activities. It's calculated by multiplying your BMR by an activity factor that reflects your lifestyle and exercise habits.
How much protein do I need per day?
For active individuals, the recommended protein intake is 1.6-2.2 g per kg of body weight (or 0.8-1.0 g per pound). This calculator uses 1.6 g/kg as the base and adjusts based on your goal.
How much fat should I eat per day?
Fat should make up about 20-35% of your total daily calories. For weight loss, aim for the lower end (20-25%). For maintenance, 25-30% is typical. This calculator adjusts fat based on your goal.
How many carbs should I eat per day?
Carbohydrate needs vary based on activity level and goals. For weight loss, aim for 30-40% of calories. For maintenance, 40-45%. For muscle gain, 40-55%. The calculator fills remaining calories with carbs after protein and fat are set.
What is the best macro split for weight loss?
A common split for weight loss is 30-40% protein, 20-30% fat, and 30-40% carbohydrates. Higher protein helps preserve muscle and keeps you feeling full during a calorie deficit.
What is the best macro split for building muscle?
For muscle gain, aim for 25-35% protein, 20-30% fat, and 40-55% carbohydrates. Higher carbs provide energy for intense training, while adequate protein supports muscle repair and growth.
Do I need to track macros to lose weight?
While not strictly necessary, tracking macros can help you understand your eating habits, ensure adequate protein intake, and achieve better results. Many people find it helpful for weight loss and muscle building.
How does activity level affect my macro needs?
Your activity level determines your TDEE, the total calories you burn each day. More active individuals need more calories and carbohydrates to fuel their workouts and recovery. This calculator adjusts your calorie target accordingly.
What is the Mifflin-St Jeor equation?
The Mifflin-St Jeor equation is a formula for calculating BMR that was developed in 1990. It is considered the most accurate for estimating resting energy expenditure in the general population and is recommended by the Academy of Nutrition and Dietetics.
How accurate is this macro calculator?
This calculator provides estimates based on the Mifflin-St Jeor equation and standard macro recommendations. Individual needs may vary based on body composition, genetics, and specific goals. Use these results as a starting point and adjust based on your progress.
Can I use this calculator for keto or low-carb diets?
This calculator provides a balanced macro split. For specific diets like keto (very low carb, high fat), you can adjust the macro percentages manually using the advanced options.
How do I convert grams of macros to calories?
Protein and carbohydrates provide 4 calories per gram. Fat provides 9 calories per gram. To calculate calories from macros: Protein grams × 4 + Carbs grams × 4 + Fat grams × 9 = Total calories.
Do I need to hit my macros exactly every day?
It's more important to be consistent over time than to hit your macros perfectly each day. Aim to be within 5-10% of your targets. Focus on meeting your protein goal consistently, then fill in carbs and fats based on your energy needs and preferences.
How often should I recalculate my macros?
Recalculate your macros every 4-6 weeks or whenever your weight changes significantly (5+ lbs or 2+ kg). As your body composition changes, your calorie and macro needs will also change.
What is the difference between TDEE and BMR?
BMR is the calories your body burns at complete rest (just to keep you alive). TDEE includes all daily activities, exercise, and the thermic effect of food. TDEE is always higher than BMR and is the number you should use for calorie planning.
Can I use this calculator for bulking and cutting phases?
Yes. Select "Gain Weight (Build Muscle)" for bulking — the calculator adds a calorie surplus. Select "Lose Weight" for cutting — the calculator adds a calorie deficit. You can adjust the adjustment amount in advanced options.