Macro Calculator

About Macro Calculator

The Macro Calculator is a free online tool that calculates your personalized daily macronutrient targets based on your body stats, activity level, fitness goal, and preferred diet type. Macronutrients -- protein, carbohydrates, and fat -- are the three essential nutrients your body needs in large quantities to fuel energy production, muscle growth, hormone regulation, and overall health.

This calculator uses the scientifically validated Mifflin-St Jeor equation to estimate your Basal Metabolic Rate (BMR), then multiplies it by an activity factor to determine your Total Daily Energy Expenditure (TDEE). From there, it adjusts calories based on whether you want to lose weight, maintain weight, or build muscle, and splits those calories into protein, carbs, and fat according to your chosen diet type.

Whether you are following a balanced diet, low-carb plan, high-protein regimen, keto diet, or Mediterranean approach, this tool provides precise gram targets for each macronutrient along with a visual breakdown. It supports both metric (kg/cm) and imperial (lbs/in) units and displays your BMR, TDEE, and protein-per-kilogram ratio for deeper nutritional insight.

Key Features

• Calculate personalized protein, carbohydrate, and fat targets in grams per day
• Uses the Mifflin-St Jeor equation for accurate BMR estimation
• Five activity levels from sedentary to extremely active
• Three fitness goals: lose weight, maintain weight, or build muscle
• Five diet types: Balanced, Low Carb, High Protein, Keto, and Mediterranean
• Support for both metric (kg/cm) and imperial (lbs/in) measurement systems
• Visual macro breakdown bar showing protein, carbs, and fat percentages
• Displays BMR, TDEE, and protein-per-kilogram ratio
• One-click copy of results to clipboard for meal planning apps or notes
• No account required, no data stored, and completely free to use

How to Use

1. Select your unit system: Choose between Metric (kg/cm) or Imperial (lbs/in) depending on your preference.
2. Enter your body stats: Provide your gender, age, weight, and height. The calculator uses these to estimate your Basal Metabolic Rate.
3. Choose your activity level: Select the option that best matches your weekly exercise and daily movement patterns.
4. Set your fitness goal: Pick Lose Weight (-500 cal deficit), Maintain Weight, or Build Muscle (+300 cal surplus).
5. Pick a diet type: Select from Balanced, Low Carb, High Protein, Keto, or Mediterranean to determine your macro split percentages.
6. View & copy results: Click "Calculate Macros" to see your daily calorie target and macro breakdown in grams. Use the copy button to save results.

Use Cases

• Weight loss planning: Calculate a calorie deficit with optimal protein to preserve muscle mass while burning fat effectively.
• Muscle building: Determine the right caloric surplus and high-protein targets to support hypertrophy and recovery.
• Keto diet tracking: Get precise fat, protein, and carb gram targets to maintain ketosis with the 25/5/70 macro split.
• Athletic performance: Optimize carbohydrate intake for high-intensity training while ensuring adequate protein for recovery.
• Meal prep guidance: Use the gram targets to plan weekly meals that consistently hit your macro goals.
• Nutrition coaching: Provide clients with personalized macro targets based on their individual stats and goals.
• Diet comparison: Switch between diet types to compare how different macro splits affect your daily gram targets.
• General health maintenance: Use the balanced diet option to ensure a well-rounded nutritional intake for everyday wellness.

Frequently Asked Questions

Tips & Best Practices

• Prioritize protein: Regardless of your goal, aim for at least 1.6-2.2g of protein per kilogram of body weight to support muscle maintenance and recovery.
• Be honest about activity level: Overestimating your activity level will inflate your calorie targets. Choose the level that reflects your actual weekly routine.
• Adjust based on progress: Use the calculated macros as a starting point. If you are not seeing results after 2-3 weeks, adjust calories up or down by 100-200 kcal.
• Track consistently: Use a food tracking app alongside this calculator to ensure you are hitting your daily macro targets accurately.
• Do not cut calories too aggressively: A deficit of more than 500-750 calories per day can lead to muscle loss, metabolic slowdown, and poor energy levels.
• Recalculate periodically: As your weight and activity level change, recalculate your macros every 4-6 weeks to stay aligned with your evolving goals.