What are macronutrients (macros)?

Macronutrients, or 'macros,' are the three core nutrients your body needs in large amounts for energy and function: protein, carbohydrates, and fat. Protein builds and repairs tissues (4 calories/gram), carbohydrates are the primary energy source (4 calories/gram), and fats are essential for hormone production and vitamin absorption (9 calories/gram).

How do I calculate macros for keto?

A standard ketogenic (keto) diet follows a very low-carbohydrate, high-fat, and moderate-protein ratio. The typical breakdown is about 70-75% of calories from fat, 20-25% from protein, and only 5-10% from carbohydrates. This forces the body into a state of ketosis, where it burns fat for fuel instead of carbs.

What is IIFYM (If It Fits Your Macros)?

IIFYM, or 'If It Fits Your Macros,' is a flexible dieting approach where you can eat any food you like as long as it fits within your daily targets for protein, carbohydrates, and fat. It prioritizes the quantity of macronutrients over the specific food source, allowing for more dietary freedom and sustainability.

Macro Calculator

Q: What is the best macro ratio for weight loss?

There is no single 'best' ratio, but a common starting point for weight loss is a balanced split like 40% carbs, 30% protein, and 30% fat. A higher protein intake is often beneficial as it increases satiety (feeling full) and helps preserve muscle mass during a calorie deficit. Our calculator provides 'Low Carb' and 'High Protein' options that are effective for weight loss.

Q: How often should I recalculate my macros?

It's a good practice to recalculate your macros every 4-6 weeks or after every 10 lbs (about 4-5 kg) of weight change. As your body weight and composition change, your energy needs (TDEE) also change, requiring an adjustment to your calorie and macro targets to continue making progress.

Your free, simple tool to calculate daily macros for your specific fitness goal.

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The Ultimate Guide to Calculating and Tracking Your Macros

Welcome to the most accurate and easy-to-use macro calculator for 2025. Understanding macronutrients—protein, carbohydrates, and fat—is the single most effective strategy for transforming your body. Unlike restrictive diets, tracking macros gives you the flexibility to eat foods you enjoy while still achieving your fitness goals, whether that's weight loss, muscle gain, or simply maintaining a healthy lifestyle. This guide will explain everything you need to know.

What Are Macronutrients? A Simple Breakdown

Macronutrients (or "macros") are the nutrients your body requires in large amounts to produce energy and function correctly. Each one plays a unique and vital role.

Protein (4 calories per gram): The building block of life. Protein is crucial for building and repairing tissues, especially muscle after a workout. It also supports immune function, hormone production, and is highly satiating, meaning it keeps you feeling full and satisfied.
Carbohydrates (4 calories per gram): The body's preferred source of energy. Carbs fuel your brain, muscles during exercise, and all daily activities. They are broken down into glucose for immediate energy or stored as glycogen for later use.
Fat (9 calories per gram): The most energy-dense macro. Healthy fats are essential for producing hormones (like testosterone), absorbing fat-soluble vitamins (A, D, E, K), protecting organs, and maintaining brain health.

How to Use This Macro Calculator: A Step-by-Step Guide

Our IIFYM (If It Fits Your Macros) calculator removes all the guesswork and complex math. Follow these simple steps to get your personalized plan in seconds:

Enter Your Details: Input your age, gender, height, and weight. The calculator supports both U.S. and Metric units for your convenience. Your personal stats are the foundation for calculating your base metabolic rate.
Select Your Activity Level: Be honest here. This is one of the most critical factors. It multiplies your base metabolism to estimate your total daily energy expenditure (TDEE), or your maintenance calories.
Choose Your Goal: Do you want to lose, maintain, or gain weight? Select your goal to create the right calorie deficit (for weight loss) or surplus (for muscle gain). A 500-calorie deficit per day typically results in 1 lb of weight loss per week.
Review Your Custom Results: The calculator first provides your target daily calories. Below, it generates several macro plans (like Balanced, Low Carb, and High Protein) so you can choose the eating style that best suits your preferences and lifestyle.

Macros for Different Goals: Cutting, Bulking, and Maintenance

Your ideal macro split will change depending on what you want to achieve. Here’s a general overview of how to set up your macros for each primary fitness goal.

Macros for Weight Loss (Cutting)

To lose fat, you must be in a calorie deficit. A high-protein diet is extremely effective during a cutting phase.

Protein: Keep it high (30-40% of calories) to preserve muscle mass and increase satiety, which helps manage hunger.
Fat: Don't go too low. Aim for 20-30% of calories to support hormone function.
Carbs: These will make up the remainder (30-50%). Adjust carbs based on your energy levels and workout performance.

Macros for Muscle Gain (Bulking)

To build muscle, you need a calorie surplus and adequate protein for repair and growth.

Protein: Aim for 30-35% of your calories to provide the necessary building blocks for new muscle tissue.
Carbs: Keep carbs high (40-55%) to fuel intense workouts and replenish glycogen stores, which is critical for recovery and performance.
Fat: These will fill the rest, typically 20-30% of your daily calories.

Frequently Asked Questions (FAQ)

What is the best macro ratio for weight loss?

While there's no single "best" ratio, a great starting point for fat loss is 40% carbohydrates, 30% protein, and 30% fat. The high protein intake helps control hunger and prevents muscle breakdown. The "Low Carb" and "High Protein" plans from our calculator are designed for this purpose.

How do I calculate macros for a keto diet?

A ketogenic diet requires a specific macro split to induce ketosis. The standard ratio is approximately 70% fat, 25% protein, and 5% carbohydrates. This extremely low carb intake forces your body to use fat as its primary fuel source.

How often should I recalculate my macros?

It's wise to recalculate your macros every 4 to 6 weeks, or after every 10 lbs (about 4-5 kg) of weight you lose or gain. As your body changes, your energy needs will also change, and your macros must be adjusted to keep making progress and avoid plateaus.

Does it matter where my macros come from?

While IIFYM allows flexibility, prioritizing nutrient-dense, whole foods will always yield better health outcomes. Aim to get the majority of your macros from sources like lean meats, fish, whole grains, fruits, vegetables, and healthy fats like avocado and nuts. Use processed foods sparingly to fill the remaining gaps.