Carb counting is a necessary skill for anyone looking to manage their blood sugar. While it may seem a bit daunting at first, it’s easier than you think once you understand the basics. This guide will break down the steps to help you count carbs with confidence and ease.
Carbohydrates, often shortened to just "carbs", are one of the main nutrients our bodies need for energy. They’re found in a wide variety of foods, including grains, fruits, vegetables, and dairy products.
Carbs can be broken down into two types: simple carbs (like pure sugar) often found in very sweet drinks, candies, and desserts, and complex carbs (like whole grains) found in foods such as whole wheat bread, brown rice, oats, and starchy vegetables like potatoes.
Complex carbs take longer to digest, providing a more sustained energy release compared to the quick spike in blood sugar that comes from simple carbs. Keep this in mind because we'll talk more about it later, but for now let's look at some basic carb counting.
Both types of carbohydrates can impact your blood sugar levels, so knowing how many carbs are in the food that you are eating is a critical piece of information so that you can then give yourself the correct amount of insulin, preventing dangerous spikes or drops in blood sugar. Accurate carb counting keeps blood sugar stable and helps with overall diabetes management.
Ready to begin? Keep reading for a step-by-step guide on how to count the carbohydrates in the food that you eat.
The carb counting formula is pretty simple. Don't worry, we'll walk through each step below, but for those looking ahead, this is the math that we'll be doing:
Net Carbs = (Total Carbohydrates - Dietary Fiber - (Sugar Alcohol ÷ 2)) • Number of Servings
It does look at little complicated, but don't give up just yet, it's actually way more straightforward than it appears. Keep reading!
Before we can begin carb counting, we'll first need to find the nutrition information for the food we're planning to eat. For most commercially packaged foods, this can be found on the nutrition label somewhere on the packaging, but for fresh produce or homemade food you may need to do some detective work. Read the section at the end of this article about what to do for foods that don't have nutrition labels.
In the meantime, we'll use this example nutrition label. Click here to view a high-resolution version of this image.
Once we have the nutrition information, we want to make sure that the amount of food that we have the nutrition information for is the same as the amount that we are going to eat. If it's different we'll need to keep this in mind for a later step.
For this example we'll just eat one serving to keep it simple.
The next thing to look for in carb counting is the total number of carbohydrates in one serving of the food. This number is simply labeled "Total Carbohydrates".
For this label, the amount of total carbohydrates is 23 grams.
From this amount of total carbohydrates, we'll subtract the amount of dietary fiber. Fiber is a type of carbohydrate, but our bodies can't process and digest it, so it won't affect our blood sugar, which is why we remove it from the carb count. Dietary fiber can be found right below the total carbohydrates line.
For this label, the amount of dietary fiber is 14 grams.
Similar to fiber, our bodies also can't process sugar alcohols that well, but they will affect our blood sugar slightly more than fiber will, which is why we subtract half of the total amount of sugar alcohols from our carb count. Not every food will have sugar alcohols, so you may not always need to count this value.
For this label, the amount of sugar alcohol is 6 grams.
Now that we have all of the numbers we need we can plug them all into the equation.
Net Carbs = (Total Carbohydrates - Dietary Fiber - (Sugar Alcohol ÷ 2)) • Number of Servings
Net Carbs = (23 grams - 14 grams - (6 grams ÷ 2)) • 1
And if we do a little bit of math to simplify things out...
Net Carbs = 23 grams - 14 grams - 3 grams
Net Carbs = 6 grams
Our carb count comes out to 6 grams per serving of net carbs. We call this value "net carbs" because it represents the number of total carbohydrates minus all of the things that our body can't process.
And that's it! Carb counting doesn't get any more complicated than that. If you're interested in practicing your carb counting skills you can find tons of example problems linked below, or if you want to learn a little more about why we do all of that math (especially with sugar alcohols), keep reading!
Click here to view some online carb counting practice problems to help you hone your skills!
Unfortunately, many foods do not come with nutrition labels, especially the fresh fruits and vegetables you should (hopefully) be eating frequently. If this is the case, there are several resources available to help you calculate or estimate the number of carbohydrates in the food item.
For foods that you commonly eat, you can also write them down in a special log for quick reference to avoid having to search for them each time. Try using the favorite foods log found on the Charts & Logs page.
Maintained by the USDA, FoodData Central is a database with full nutrition information for nearly half a million different foods, including fresh produce and vegetables that don't come with nutrition labels.
The WebMD Food Calculation is an easy to use search tool with nutrition for many common fresh, packaged, and restaurant foods.
Similar to FoodData Central, the Nutritionix Database contains nutritional information for over 1,000,000 different foods which makes it a great resources for carb counting.
Yet another (but smaller) database of common foods designed specifically for counting carbohydrates. A super useful tool for reducing the amount of carb counting math you need to do!
Fiber, unlike most carbohydrates, isn't fully digested or absorbed by the body, meaning it has little to no impact on blood sugar levels. For this reason, when counting carbs, we subtract the grams of fiber from the total carbohydrate count.
Fiber is commonly found in plant-based foods, especially fruits, vegetables, whole grains, legumes, and nuts. Foods like apples, broccoli, oats, and beans are also all rich in fiber.
Sugar alcohols are commonly used as sweeteners in many sugar-free or reduced-sugar foods. While they so provide fewer calories than regular sugar, they still have some impact on blood sugar levels. Typically, only half of the grams of sugar alcohols are counted as carbs, but some schools of thought instead subtract the total number of sugar alcohols (just like we did with fiber). Use whichever of these options your doctor recommends specifically for you.
Sugar alcohols can also go by different names, often using the common name of the chemical rather than the generic umbrella term "sugar alcohol". Some names that you might see include erythritol, mannitol, maltitol, xylitol, or sorbitol.
Although sugar alcohols can be confusing, fortunately you likely won't come across them that often. As of writing this article and having been carb counting for nearly six years, I've only seen sugar alcohols on nutrition labels once or twice!
