Macro Math Is Hard: Understanding Nutrition Labels & Calculating Macros From Food

The other day, I spent a couple of hours explaining to some clients about how to read a food label and how to figure out how much grams of protein, carbs and fat were in any given serving of food. Some of you math geniuses already know how to do this and that’s great but there are a lot of you that still struggle with the macro math.

Hopefully, after reading this guide, you’ll have a better understanding of how to figure out your macros from nutrition data. I’ll also share two hacks that I use to make the macro math easier.

I'm going to try to explain this as simply as I can 🙏🏽

Here goes...


Step 1: Understand the food label

To figure out how much food you need or have on hand, you need to understand how to read a nutrition label. Here is a standard nutrition label for some whole-grain pasta.

 A standard nutrition label

A standard nutrition label

I’m not going to go into detail about all the things on the label, just the important ones needed to figure out the macros. We’re also not concerned with % Daily Values because it probably doesn’t apply to you.

Serving Size

This is the amount of food by that’s considered ONE SERVING. It can be listed as either a volume in cups, teaspoons, tablespoons, liters, milliliters, or fluid ounces or by weight in grams, ounces, or pounds. This is probably the most important number because every other value listed on the label is based on the serving size.

SUPER IMPORTANT: Unless otherwise stated, the serving size is based on whatever state the food is in inside the package. This is important because if the food is not cooked or prepared inside the package for example, the serving size and all the nutrition data is based on the uncooked weight.

Servings per Container

The number of servings in the entire container based on the serving size. This is useful to know if you eat an entire package of something  and want to know how much you ate.

You’d take the number of servings per container times the protein, carbs, fat or calories listed on the label.


If you’re tracking calories this is where you would look to find the number of calories in one serving. If you’re tracking macros, just move on.

Calories from fat

How many calories from fat there are in a serving. Not sure if or why anyone tracks this but it’s based on the fact that 1 gram of fat = 9 calories.

Total Fat

The grams of the fat macronutrient in one serving. Some labels have fat broken down by type. I’m not going into detail about the different types for this guide. For figuring out your macros, just pay attention to the total.

Cholesterol, sodium, potassium

Good to know how much you’re getting but again, not necessary for figuring out your macros. Move along.

Total Carbohydrate

The grams of the carbohydrate macronutrient in one serving. Again some have this broken down into fiber, sugar, and “other” carbs. Don’t worry about the breakdown, just focus on the total.


The grams of the protein macronutrient in one serving.


Important to know but not necessary for calculations.


Important to know but again, we don’t need them for calculations.


Step 2: Get a Food Scale and Measuring Cups

To track macros most effectively, you really need to weigh or measure your food since food labels list servings in weights or volumes. You can either use a food scale to measure the weight or measuring cups or spoons to measure the volume. I recommend having both on hand and using a food scale for solids and cups/spoons for liquids like milk or oils.

A quick Amazon search will bring up a variety of food scale options. Get a digital one and if you'd rather not deal with batteries, make sure it has an AC adapter. 


Step 3: Calculate your MacroNutrients

Once you understand how to read a label and have tools to measure the food, you can figure out how much protein, carbs, & fat (macros) you have present.

Let’s say you need 25 grams of carbs for your meal and you want to get it from the whole-grain pasta. Here's the label again. 


Here’s the “Master Formula” for figuring out how much of the food you need for any given amount of the macronutrient.

The Master Formula is:

How many grams of the macro you need ÷ The number of grams of the macro on the label

Then take this number and multiply by the serving size to get the amount of food you need.

In this example, to get 25 grams of carbs from this food we divide 25 grams by 29 grams. 25 grams is the amount of carbs you need and 29 grams is the amount of carbs on the label.

Just punch that into the calculator.

25 ÷ 29 = 0.86

Take the result, 0.86, and multiply by the serving size on the label, 57 grams. Punch that into the calculator.

0.86 x 57 grams  = about 49 grams of the uncooked pasta

Or if you use the ounces as listed:

0.86 x 2 ounces = 1.7 ounces of uncooked pasta

This means that 49 grams or 1.7 ounces of the uncooked pasta will provide you with 25 grams of carbs. Even, if we threw the pasta into a pot and cooked the 49 grams, regardless of what it weighs after we cooked it, we would still be getting 25 grams of carbs. 

But what about the protein and fats?

Note: The following method works for figuring the other macros and also works if you just weigh out any amount on the scale and want to know much protein, carbs and fat you have.

First, take the amount of food you have weighed out and divide it by the serving size listed on the label.

In this case, you have 49 grams of the pasta. Divide 49 grams by the serving size listed on the label, 57 grams.

49 grams  ÷ 57 grams = 0.86

Then multiply the resulting number by the total fat listed to find the fat, the total protein listed to find the protein and the total carbs listed to find the carbs.

For protein: 7 grams (on the label) x 0.86 = 6 grams protein

For fats: 0.5 grams (on the label) x 0.67 = 0.4 grams fat (since it's less than 1, I would count as 0)

For carbs: 29g (on the label) x 0.86 = 25g carbs

So for your 49 gram serving of the food, you have 25 gram carbs, 6 grams protein, 0 g fat.

Here's a shortcut. You can quickly calculate the other two macros by just calculating one of the macros. Use the Master Formula. 

How many grams of the macro you need ÷ The number of grams of the macro on the label

Then multiply the result by the the totals listed on the label for the other two macros. 


Let’s review:

If you need X grams of any macro from any particular food, the formula is:

X grams of the macro you need ÷ X grams of the macro listed on the label

Then multiply that number by the serving size to get the amount of food you need.

To figure out the macros of any amount of food you put on the scale:

Take the amount of food you have weighed out  ÷ the serving size listed on the label

Multiply the resulting number by the total protein, carbs or fat listed on the label to get the macros

Should I figure out my macros for cooked or uncooked foods?

Some foods will be uncooked in the package but you eat them cooked. This is especially true for whole grains, dried goods like pasta, and meat. Should you use the cooked or uncooked nutrition data?

It largely doesn’t matter if you base your math on the cooked or uncooked weight of foods as long as you’re being consistent in which one you use.

To be exact, you’ll need to weigh and record the food weight before and after cooking. If you have these two numbers, you’ll always be able to figure out what you have based on the nutrition label.

Example: Pasta bulk meal prep

Let’s say you need 50 grams of carbs from the pasta and you need to make 7 meals.

Go back to the formula:

50 grams ÷ 29 grams = 1.7

Multiply that number times the serving size on the label. Based on the label, the serving size is 57g.

1.7 x 57 = 97 grams of uncooked pasta will give you 50 grams of carbs.

If you need to make 7 meals, just multiply the number 7 by 97 grams to get the total amount of pasta you need to weigh out and cook.

7 x 97 grams = 679 grams uncooked pasta

Cook the pasta and weigh the final batch. Let’s say it swells up to 800 grams. You still have 7 servings total in the batch.

Take the cooked weight and divide by your total servings, 7.

800g ÷ 7 = 114 grams cooked pasta = 50 grams carbs.

Now you know exactly how much to put into your containers. The same process works for meat or anything that comes uncooked and you have to cook. Remember, as long as you weigh the food before and after cooking, you can figure out how much food to eat.

What if the food doesn’t have a label?

Most whole, unprocessed foods won’t have a label. You can still get the nutrition information, but you’ll have to look it up yourself.

There are several sources I recommend like:

Important: Whatever source and listing you use for the nutrition data for something without a label, make sure you use the same source and listing.

If you’re making a dish with a recipe, use My Fitness Pal’s recipe builder in the app to create your own label and base your calculations off of that.

Pro tips from the laziest macro counter alive

Make macro cheat sheets.

Once you figure out the macro math for a food item, make a cheat sheet for the food in standard multiples of ½ serving, 1 serving, 1.5 servings and 2 servings.

For example: a long time ago I figured out that 175g of cooked white rice = 50 grams of carbs. 

So I made a cheat sheet for the rice for other serving sizes. 

Like this:

½ serving or  87.5 grams of rice =  25 grams carbs

1 serving or 175 grams of rice =  50 grams carbs

1.5 servings or  263 grams of rice = 75 grams carbs

2 servings or 350 grams of rice = 100 grams carbs

With a cheat sheet, I never need to measure the cooked and uncooked weight anymore. I just need to make the food and put how much I need on my plate. You can do this with any food. Post your cheat sheet somewhere you can quickly reference like on the fridge and it can save you a lot of time from doing more math.

Use a quick and dirty Conversion for cooked meats

We usually don't eat raw meat but for most meat, the nutrition data is for raw. Raw and cooked meat are very different. For some proteins you can find the cooked value online, but for some meats you can’t. I’m lazy, don’t like digging, and would rather just eat so I just use a simple conversion to figure out how much protein I have in my cooked portion of meat. It’s not 100% accurate,  but it doesn’t need to be. It’s close enough and consistent which is what matters in the long run.

Just take the raw weight of your meat and multiply by 0.75 to get your cooked weight. Put the cooked amount on your plate and use the raw meat nutrition data.

For example: if 4 ounces of raw 93% lean ground beef has 23 grams of protein, multiply the weight by 0.75 and you’ll need 3 ounces of cooked ground beef to get 23 grams of protein.

If you need to go from cooked weight to raw because you have the cooked nutrition data, just multiply the cooked weight by 4/3 to get the amount of raw meat you need. 


Phone a friend

If you’ve made this far without ripping your hair out from all the math, and still don’t “get it”, but you still want to count macros, there’s still hope. Phone a good friend or get a coach who really understands the math and ask them to help you figure out the what you need. You can still make it work :)

 You still trying to do macro math...

You still trying to do macro math...

Good luck!


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