Free Macronutrient Calculator

How to Determine Your Macros for Weight Loss and Muscle Gain

Why This Macronutrient Calculator?

If you’re reading this then you know that macronutrients are an important factor in your diet. But how do you find your macros with dozens of fad diet variations?

The truth is, most macronutrient calculators are horribly inaccurate. Because they use outdated formulas with little personalization.

Another problem is that you get only one set of macro targets. Why would you eat the same on days you rest vs. days you workout? You wouldn’t… or at least you shouldn’t.

For all these reasons, you need a better macronutrient calculator that gives you:

  • More accurate macro targets

  • Macros that adjust to your activity level

  • Sustainable meal plan for fat loss & muscle gain

macronutrient calculator

How Do You Calculate Your Macros?

First, it’s important to realize that calories are more important than macros. After all, macros don’t matter if you eat too little or too much!

bodybuilding nutrition simplified

Bodybuilding Nutrition Simplified

Therefore, our macronutrient calculator uses several factors to create your personalized calorie balance. From there, we calculate your macro targets based on a percentage of calories. Then convert that to grams of carbs, fat, and protein.


Think of your body as a hybrid car. When you step hard on the accelerator, you use mostly gas and very little electricity.

Similarly, carbs are the gasoline that fuels intense physical activity. So carb intake should adjust with your activity level. Higher on days you workout, and lower on days you rest.

How to Use Carb Cycling

In addition, carb intake should match your goal. In other words, more carbs for muscle building and fewer carbs for fat burning.

Therefore, carb intake varies the most of all macronutrients. Anywhere from 5% to 55% of daily calories.


Let’s continue the hybrid car analogy. In this case, fat is the electricity that fuels easy cruising at constant speed.

As a result, fat intake is the inverse of carb intake. Lower fat on days you workout, and higher fat on days you rest.

Fat intake varies from 20% to 60% of daily calories.


In keeping with the car theme, protein is less like fuel and more like spare parts. When your car breaks down you need parts to repair it.

In the same way, when your body breaks down from workouts and stress, you need protein to rebuild it.

In addition, protein prevents muscle breakdown during calorie restricted diets. So you need adequate amounts for both fat loss & muscle gain.

Protein intake should be fairly constant around 30% of daily calories.

As you can see, your macro targets depend on your daily activity level. As well as other factors like your body composition, body type, and fitness goals.

So how do you put all this together and determine your macros? That’s where the macronutrient calculator comes in.

How the Macronutrient Calculator Works

In order to find your macros, we ask a few simple questions about your body type, activity level, and lifestyle.


First, tell us a little bit about your body. Including your current weight, gender, body composition, and body type.

A point often overlooked is that lean mass is the biggest contributor to your calorie needs. However, you might not know your body composition numbers.

Therefore, we made it easy to find your body fat percentage with a simple visual comparison. Also, if you’re unsure about your body type, take this easy quiz:

macro calculator by body type

Activity Level

Next, we give you a few options to describe your daily activity. Like whether you sit or walk alot during the day. This is your baseline excluding exercise.

Then you tell us how many days per week you exercise. And you choose the duration and type of exercise.


Lastly, you provide some information about your schedule and your goal. This allows us to adjust your macros for fat loss, muscle gain, or body recomposition.

Get Your Macros

Click the button below to get your personalized macros for fat loss and muscle gain.

In addition, you can get a personalized macro meal plan. Follow your personalized plan and see results in 30 days!

Get Your Macros

About the Author

Jeremy Fox  –  Founder of Nutritioneering, Engineer, CPT, Bodybuilder, Coach

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