Example: Calculating Carb Count Per Serving – MyFitnessPal Tips & Tricks


A lot of people tell me they find keto macros, low carb meal tracking and/or MyFitnessPal to be complicated or frustrating.

I’m a macro tracking junkie 🤓 so here are a few tips to make it easier! Plus a lot of other fun facts & interesting tips mixed in…

In this example I’m using chopped onions, because lately I’ve fallen in LOVE with grilled or sauteed onions as an ingredient in my keto meals. 🧄

I found a great (super convenient) bag of already chopped onions in the freezer section at the grocery store this week too, which was nice:

Pictsweet Chopped Onions

🛒 I love convenient frozen produce like this (where that is the ONLY ingredient) as I don’t cook often and I’m cooking for one.

It’s less messy than chopping a fresh onion, plus less waste since I can simply portion out what I’m going to use each time – and not worry about any going bad before I can use it all.

Frozen Chopped Onions Keto Recipe Ingredients

Stay tuned for upcoming food diaries to see what I make with the chopped onions!

I’m thinking: BBQ bacon onion burgers, spinach & cheddar omelets with sauteed onions, bacon & onion avocado cakes – and crustless quiche cups to start. 😍

The serving size for these chopped onions is 2/3 cup though, which I wouldn’t use (unless it was in a larger recipe).

So I had to do a little figuring on how to enter this into MyFitnessPal, especially when I’m just going to add a tbsp to an omelet for example – or anything less than a full 2/3 cup serving.

Pictsweet Frozen Chopped Onions Nutrition Facts

Most of the entries for this product were WRONG in MyFitnessPal too. That’s something else you want to double check, which I’ll show you in a second – along with how to log/track fresh produce that doesn’t have labels.

I had to do the exact same double checking & math for my fresh & frozen blueberries, which I enjoy often – but in much smaller amounts than the typical serving size, since I eat those “in moderation” in my keto diet.

It’s not just about the serving size, but also the unit of measure…

Things like almonds and macadamia nuts, sugar free chocolate chips, blueberries and diced or chopped onions don’t fit in a measuring cup right.

They’re all different sizes or shapes and weights, so you can’t count them out for accurate macros either.

There’s also space between them in a measuring spoon or measuring cup. And I don’t know about you, but AIR is NOT one of the macros I’m tracking. 😁

Blueberries Nutrition Facts - Keto Kitchen MyFitnessPal Tips

As you can see on the nutrition facts for my bag of organic frozen blueberries above, a serving size of 3/4 of a cup is 19 carbs – or 15 net carbs.

Obviously I wouldn’t eat that many as a serving..

3/4 cup = 12 TBSP (there are four tablespoons in 1/4 cup). When you divide the 140 grams of blueberries by 12, you get 11.67 grams as a measurement “per tbsp” of blueberries.

That makes them approximately 2.5 net carbs for 1/8 cup (two tbsp / 23.34 grams) which is the perfect amount to garnish your low carb yogurt – just to give you a realistic example.

Measure vs Weigh: Grams & Ounces Are More Accurate

More often than not you’re cheating yourself out of some delicious bites if you measure vs weigh, as I proved in this comparison on chocolate chips. 😉

Keto Portions: Weighing vs Measuring

What fits in a tablespoon (1 TBSP serving) is NOT the same as the amount of chocolate chips you get to enjoy if you weigh it in grams instead. 😉

And let’s be honest: more chips is always better than less chips! 🙂

I use an Ozeri Kitchen Scale. It’s small, inexpensive and super convenient.

Back to those delicious chopped onions… 😍

Here is the label again, showing that a serving is 2/3 cup (or 85 grams):

Pictsweet Frozen Chopped Onions Nutrition Facts

I’m no kitchen whiz, but fortunately Google is AWESOME for quick conversions!

I went to Google and did a quick cup-to-tbsp conversion:

Cup to TBSP Conversion - Keto Kitchen Tips

🧮 One serving is 2/3 cup, or 85 grams.

That equals 10.667 TBSP.

So a TBSP is approximately 8 grams and 0.6 net carbs (or 0.7 total carbs). 🧄

Keto Kitchen Conversions

This quick math allows me to determine how to best log the amount of chopped onions I use while cooking.

Let’s say I use one tablespoon (1 TBSP) or eight grams in my breakfast omelet or scrambled eggs.

I can use the drop down box in MyFitnessPal to change the serving size to one gram, and eight servings, for the 8 gram amount I used:

MyFitnessPal Entries For Different Serving Sizes

Onion Nutrition Facts for Keto Recipes

Keto Macros for Chopped Onion

Here’s how I get net carbs in MyFitnessPal.


Mind Your Macros..

(Don’t Rely on MyFitnessPal!)

The entries in any of our nutrition or meal tracking apps is mostly entered by other people, and many of those entries contain errors.

Tip: ALWAYS compare an entry to your own label! If it’s incorrect, you can edit it – or simply find an accurate entry for that food item.

The bar code scanner in MyFitnessPal is super convenient to quickly enter packaged foods too, such as the chopped onions or frozen blueberries. But again, not all of the entries are correct so be sure to double check those by your label as well.

For fast food or chain restaurants, double check your entries by their website. They publish their nutrition facts online, and many even have nutrition calculators for special orders.

For fresh produce or foods without labels…

Google fresh produce to double check the nutrition facts and macronutrients for any food without a label.

Simply do searches like “avocado nutrition facts” or “blueberries nutrition facts” or “onion nutrition facts” (quotes not necessary) for fresh produce you get at the store or from your garden / in the wild.

Search fresh produce nutrition facts

You can use this information to create your own entry for meals or foods you eat often, so you can easily log that food in the future once it’s in your account.

You only have to double check the entry, or in some cases (like this one) figure out the serving conversion, one time.

I plan on using the chopped onions often (like I have the blueberries, for years now), so once I enter it for the first time… it’s now saved in “my foods” in my MyFitnessPal account, so I can easily add it anytime I use that food or ingredient again.

MyFitnessPal Tips for Keto Meal Tracking


Also see: What Are Macronutrients? How To Use Your Macro Calculator Without Stressing Out

If you have any questions about using MyFitnessPal, Meal Tracking or Keto Macros, leave a comment. I’m happy to help any way I can, and would love to make this easier on you if you’re struggling with tracking – or avoiding it for some reason. 😉

Another interesting point you may have noticed on the labels I shared with you above…

Blueberries and Onions are both a good source of potassium!

Someone asked me this week about electrolytes, magnesium & potassium – and whether I use supplements for any of those things.

I don’t.

I’ve been eating keto for 9 years now and have never taken electrolytes or supplements.

On that point, be careful about the advice to drink too much water as that can flush out your sodium & electrolytes and cause things like headaches and leg cramps (among other symptoms).

If you have any questions about that, or thoughts on the topic, I’m all ears. 👂🙂

In addition to the chopped onions and blueberries, I got A LOT more low carb groceries this week…

Stay tuned for a new post with a full list of what I stocked my kitchen with… and what I plan to cook over the next couple of weeks. 😉

Fun, simple, EASY meal ideas coming soon!

Lynn Terry,
aka @LowCarbTraveler


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About Lynn Terry

I love making the low carb diet EASY for people with a busy lifestyle (like me!) with my KISS / Keep It Simple method. :) About Lynn Terry: Host of the Low Carb Challenge
This entry was posted in Low Carb Foods and tagged , . Bookmark the permalink.


2 Responses to Example: Calculating Carb Count Per Serving – MyFitnessPal Tips & Tricks

  1. Dottie Rathbun says:

    I know nothing about My Fitness Pal
    I do have a food scale, will check tomorrow to see if I need a better one
    Am excited to hear how to do this and your grocery list
    I have tried low carb but never seem to stick with it, I have really bad knees and use a Scooter to get around it makes excising difficult . Having a person as experienced as you will help tremendously ,
    Dottie Rathbun

    • Lynn Terry says:

      Hi Dottie,

      I didn’t exercise at all in the beginning. I lost all of my weight just eating very low carb. I also kept it really simple: 20 net carbs max. That worked for me!

      I was in chronic pain prior to going low carb, on pain medication and unable to do a lot of everyday things. It’s amazing how much carbs promote inflammation in our bodies, and how much better you feel eating low carb consistently!

      Let me know if you have any questions, or if there’s any way I can help. 🙂

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