How to Calculate Your Macros (Funsized Method)

You’re probably here because you want to know how many calories and macros you need in order to lose fat and build muscle while working out.

With so many macronutrient calculators on the internet, how are you supposed to know which to use? Each calculator seems to give different guidelines, so it can be difficult to know what’s accurate — or where to start!

Well, now your Funsized Fairy God-sister is here to walk you through my proven method for calculating my own and dozens of my petite clients’ macros.

FUN[SIZED] FACT: It might seem like macro counting is gaining popularity on social media, but the concept is not exactly new. Macros have been “around” nearly as long as calories, and tracking them has long been practiced in the fitness and dieting world. It’s become widely popularized and easily accessible thanks to technology and free apps like MyFitnessPal and LoseIt. Before smart phones & the internet, old school bodybuilders would carry pocket calorie dictionaries, keep written journals of what they ate with corresponding the macronutrients – that means they had to do ALL the math themselves! Lucky you can have your phone do all that nasty work for you!


Before figuring out your specific macro goals, you must first be aware of how many calories you’re currently eating. (you’ll see what in a sec)

The best way to do this is to track your calories for a week. Don’t try to change anything, just simply eat how you normally would. This gives you an idea of your maintenance calorie intake. 

Now, before you “cheat” by using a calorie calculator or simply multiplying your body weight by 12-15 … let me tell you what the issue with both of those options is:

If you’re goal is weight loss and you’re already currently eating less than the calculator’s suggest amount, when you start eating those few hundred calories more, you’re likely to gain weight. Same holds true for the opposite scenario. To avoid all that, the best way to calculate YOUR calories is by tracking YOUR calories for at least a week as mentioned earlier. 

Once you find your current calorie intake, you can determine a caloric goal to work towards. This is where those calculators could actually be handy. If you find that your current intake does not match your suggested target, you may need to work on adjusting it overtime depending upon things like your body composition goal, your activity level, your sleep, etc.   (*Hint: this is when it would be beneficial to have a professional to help you!*)


Every calorie of food that you eat can be broken down into three main groups (protein, carbs, and fats). These macronutrients (or macros for short) determine things like your body composition and performance. 

There is NO standard amount of macros a petite should eat. It is different from person to person and depends on your height, weight, activity level, age and your personal goals.

The information I provide below will give you a good understanding of general guidelines to follow when getting started. Once you have learned the basic guidelines, you are totally free to explore and see what works best for you.

1. Protein

Regardless of whether your goal is muscle building, strength building, athletic performance or fat loss, studies consistently show that a relatively high protein diet is beneficial. When it comes to muscle and strength gain, studies show that high protein diets build muscle faster and contribute to more strength gains. For athletic performance, studies show that high protein diets help with faster recovery from intense athletic training sessions versus lower protein diets. For fat loss, studies show that high protein diets maintain more muscle (which helps prevent metabolism slow down) and they suppress appetite better than lower protein diets.

Although there is always an individual variance and some might not digest protein as well as others, most petites will do better if protein intake was high. 

What is high? Basically, you want to be between .8g and 1.2g per pound of body weight (there’s an ongoing debate for whether that’s lean body mass or actal body weight). For sake of ease, a good rule of thumb is 1 gram of protein per pound of body weight. 

So if you’re 150lbs, you should aim to eat 150g of protein per day. Now, if you found that you were currently barely eating 100g protein (according to that week of diligent calorie counting you did), you DO NOT want to add 50g protein right away unless you want to be insanely satiated & uncomfortably constipated. Just like training for your first ever half-marathon, you do not want to go from running 0 miles today to running 13.1 miles tomorrow. Instead, slowly & gradually increase your protein intake week by week until you reach an ideal intake. 

Generally, once you’ve reached an ideal protein intake, this macro target will generally stay about the same. 

2. Carbs and Fats will fluctuate based on your specific goals or intentions. This will vary WIDELY per individual and it’s much harder to give general guidelines. But here are a few things to consider:

  • Essential fat for most petites is around 40-70 grams a day. Some people feel better on the higher end and others on the lower end. If your carbs are very low, your fat can be much higher without the risk of eating too many calories. *As females, your fat should not be below 25% of your total calories!*
  • Vegans might need to err on lower protein (perhaps .8g per lb of body weight) which means they might feel better with higher fat & carbs than non-vegan petites.
  • For athletic and performance purposes, low carb diets are typically inferior to diets that have more carbs. If you are interested in strength or performance, you will probably do better if you have a higher ratio of carbs(40-55%).
  • Take your current carb & fat intake into consideration. Try not to take huge jumps right away to get to calculator suggested targets. Instead, make minor adjustments of your current intake in the direction that best aligns with your goal.

My most successful petite clients thrive within these ratios: 
  • 25-55% carbohydrates
  • 25-40% fats
  • 30-45% protein

Again, all of this is just a BASIS. The responsibility is on you to check in with yourself weekly to see how you’re responding to those percentages. Ex: Feeling bloated off the higher carb intake? Bring up the fat and lower the carb. Feeling constipated off the high protein? Lower the protein. Feeling crazy full all the time? Lower the fats. Your body will always give you signs and signals that tell you when things are going good or not so good.

The best macronutrient ratio is the one that works for YOU and your body. Every petite is different in their needs, body composition, genetic makeup, and overall health, which is why working 1:1 with a nutrition coach can be extremely beneficial. Not only do they keep you accountable and on track, but they help teach you about your individual body and what levels and types of nutrients fuel it best so that you’re not just taking shots in the dark with your ratios.


When setting macronutrient targets, using percentages is helpful to make sure you’re getting the right ratio/balance of all 3 macros. But when actually counting macros from day to day, you should be looking at the total number of grams per category and not the percentages. 

Here’s why you can’t *just* go by percentages: It is possible to eat the same percentage of macros at 1000 calories as you would when eating 2000 calories. Even if you’re always hitting your macro percentages, you aren’t always being consistent with your calories and since calories determine whether you’re in a deficit or surplus, it’s important to make sure they are also in check.

FUN[SIZED] FACT: Since macros make up calories, when you meet your macro targets (in grams), you’ll automatically meet your calories. 


Just like the “Couch to 5k” training program, you’ll want to make small adjustments week by week [or even month by month] and allow your body time to adjust to the new stimulus. By small, I’m talking within 2-5g adjustments (there are, of course, exceptions but for the most part, it really doesn’t take much for petite women if you’re being consistent).

Overall, calculating YOUR unique macronutrient targets is a process of trial and error. 

Try things that align most with your goals first and give it sufficient time (like more than a few days) to determine whether it’s for you or not and keep trying new things periodically. 

Furthermore, if you want to keep progressing and making body composition changes, frequently (but slightly) adjusting your macros will ensure that the body doesn’t plateau. 

The most important thing is figuring out what works best for you. If you don’t feel good eating a high-fat diet, lower your fat intake and up your carb intake. If a high carb diet is making you feel bloated and sluggish throughout the day, try eating more fats. The great thing about figuring out macros is that you get to explore what works best for your body. What works for one person may not work well for you.

In the end, tracking your macros is only one piece of the body recomposition puzzle. Make sure you are also lifting heavy, drinking enough water, getting 7-9 hours of sleep a night, and staying away from highly processed foods.

Does this sound tricky?
Working 1:1 with a nutrition coach can help take ALL the guesswork out of it and ensure that you’re on the fast-track to success!

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