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Macro Calculators: Start Where You Are.

Macro Calculators: Start Where You Are.

Macro Calculators are Just Estimates

No macro calculators from a website or even macros from an experienced coach are your perfect numbers. Yes, they can give you a good estimate, but you can do the same.

The quantity of food you need is based on two main factors:

  1. Basic Physiological Functions; and
  2. Activity (from walking around to working out).


Sure, we can make the “basic physiological functions” category more complicated (e.g., Resting Metabolic Rate, Thermal Effect of Food, etc.), but there is no real utility to do so. Essentially there is a baseline level of food you need to support some pretty basic functions. While there are ways to estimate this, it is dependent on your age, sex, lean mass, and the wildcard: genetics. Meaning, we can get an estimate based on average human data, but it won’t be 100% accurate to you.

Then there is the food you need to support daily activity. This can be highly variable between individuals (e.g., sedentary to multiple training hours per day) and even can be highly variable day to day (i.e., rest days to high volume days). The quantity of food needed to cover your activity can be estimated from calculators as well. But some of these calculators get pretty in the weeds of including all daily activities (from each household chore like washing dishes and to each element of a mixed-modal training session). The intensity at which you perform these efforts is also a factor just as much as the activity and duration. So there is going to be some inherent error in these macro calculators. Many sites resort to using more simple descriptors like “sedentary” or “very-active” that essentially become multipliers on your baseline level of calories needed for basic functions.

It is worth noting that the calculators are often not wildly off (assuming accurate inputs), but you can do better.

How to Determine Your Baseline Caloric Intake

Record what you eat for 5-7 days. I’d recommend a stretch long enough that you include days with those dietary indiscretions and natural fluctuation in activity. For example, I tracked 7 days to include a full weekend when my diet isn’t as regimented and activity is reduced. Yes, you can do this for a shorter period of time, but a week is more likely to give you a realistic number. Ideally, you just eat “naturally” during this week not trying to do anything different.

This may seem more work than just using macro calculators and getting an immediate answer. It is in the short-term, but the return on investment is that you will end up with numbers that are more meaningful to you. It already takes into account ALL of the factors above because you are the living example of them. Why leave it up to an online calculator when you have real data? This also means your starting point is likely more realistic, which will make the whole thing more sustainable.

You can just track calories, but apps like MyFitnessPal make it easy enough to get your macros as well. Here is my data for a week:

Macro calculators are needed. Data of 1 week of observing my diet.

From there take the average for calories and each macronutrient. This is your baseline. Assuming you are at a constant weight, this number of calories approximates how to maintain your current weight in light of your age, sex, lean mass, genetics, and activity!

In this case, my average was 2,331 calories/day.

How to Determine Your Macronutrient Ratio

Now you need to determine how these calories “should” be split among the macronutrients. The “40/30/30” split recommended by Dr. Barry Sears for the Zone Diet is a good place to start for a couple reasons:

  1. It provides a good basis of the macronutrients nutrients needed for the active but non-professional-one-workout-a-day crowd;
  2. It is a middle ground: tweaks on the ratios are not as major as starting at more extreme ones (say a keto diet).

“40/30/30” means 40% of the calories come from carbohydrate, 30% from protein, and 30% from fat. You can choose any macronutrient split you want, but if you don’t know where to start this is a good one for most people. Here are my calculated macronutrients based on 40/30/30 compared to what I actually ate in the sample week:

Macro calculators replacement math

Comparing your calculated average intake to your actual intake is worthwhile; someone may choose to make gradual steps towards their goal macronutrient distributions versus trying to switch immediately to them if they were very disparate (remember: sustainability is important!).

If you want to lean out, reduce your baseline by 10%. Yes, some will recommend greater percentages (e.g., 20%) for fat loss. However, one of the things I’ve found over the years is that just by recording all your intake, you generally end up eating less (despite attempts to eat “naturally”). Take an honest estimate of your recorded week; it may be that you just need to be consistent at this baseline versus reducing the caloric load even further.

And if you want to gain mass, baseline calories can increase by 10-20%. Yep, that’s it. The first step to all this stuff (as true for most things) is just starting and getting consistent in the practice. Don’t delay by trying to get it “perfect” out of the gates. It doesn’t exist and it’s more meaningful to just start where you are.

Want More on How to Figure Out How Much to Eat?

Check out the podcast episode below. 

Not only do we talk about this process in more detail, but also how to know if what you calculated is a the right amount, and reasons you might not lose weight at those macros.

4 thoughts on “Macro Calculators: Start Where You Are.”

  1. I’m curious to know if you think using my Fitbit’s average calories burned measurement per day would be a valuable way to assess how many calories I need to take in. I track my food intake but still not certain on how many calories I should base my macros off of. If my Fitbit says I regularly burn 2400 calories in a day (I wear it all the time) is fair to assume I need close to that to maintain? Right now I consume 1400-1600 calories and I’m not loosing weight but I’m worried I’m not actually eating enough for how active I am (is this even possible?) I eat a very clean, Whole Foods diet- lots of veggies (raw and cooked) and some fruit, nuts/seeds, low starch and almost no bread products and good clean sources of protein (fish, chicken, deer, elk and antelope). I’m 5’4 and weigh 133lbs. I would like to loose 5lbs-ish but trying to not get stuck on a number, and build muscle while staying lean..

    1. Eva Claire Synkowski

      Hi Arianna!
      I don’t exactly know the algorithm for Fitbit, but it’s got to be relying on standard equations based on age, sex, gender, etc., which means it’s going to have some error relative to you. This is why I really don’t recommend using them for caloric estimates… it just an estimate! As for your lack of weight loss, not sure how long you have been consistent at 1400-1600 calories, but it does take some time (e.g., I would say at least 4 full “perfect” weeks before assessing for a change). There IS the possibility you could be undereating, but that would be more of concern if you have been at 1400 cals for a significant amount of time and your caloric need is >>2000. And of course, stress and sleep come to mind as potential factors related to weight loss. As for building muscle while staying lean… it doesn’t work so perfectly that you can ONLY add muscle and no fat. Building muscle typically requires caloric surplus so some leanness is usually lost during that. Of course, this doesn’t mean tons of extra weight, but typically is a cycle of gaining some weight… then leaning out, etc. You may ultimately want to work with a macro coach to walk the process with you to get you to your goals!

      1. Thank you so much! This helps me a ton actually! It helps to hear from you and I greatly appreciate the response. I’ll keep working at it! As far as weight loss, I haven’t gone down on weight by definitely see a change in my body so that is probably more important than the number. Thanks again! I love your blog and all the information you give!

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