Photo KnowInsiders
Photo KnowInsiders

Carbohydrates provide 4 calories per gram, protein provides 4 calories per gram, and fat provides 9 calories per gram. If you know this, you can easily calculate how many calories in one gr of carb, protein and fat.

What is gram?

A gram is a unit of mass in the metric system defined as one thousandth (1 x 10-3) of a kilogram. Originally, the gram was defined as a unit equal to the mass of one cubic centimeter of pure water at 4°C (the temperature at which water has maximum density). The definition was changed when the base units for the International System of Units (SI) were redefined by the 26th General Conference of Weights and Measures. The change went into effect May 20, 2019.

The symbol for the gram is the lowercase letter "g." Incorrect symbols include "gr" (the symbol for grains), "Gm" (the symbol for the gigameter), and "gm" (easily confused with the symbol for the gram-meter, g⋅m).

Because a gram is a small unit of weight, its size may be difficult for many people to visualize. Here are common examples of objects that have about one gram of mass:

A small paperclip

A thumbtack

A piece of chewing gum

One US bill

A pen cap

One cubic centimeter (milliliter) of water

A quarter teaspoon of sugar

READ MORE: How to Convert Grams to Kilograms

1 gram (1 g) = 5 carats (5 ct)

1 gram (1 g) = 10-3 kilograms (10-3 kg)

1 gram (1 g) = 15.43236 grains (gr)

1 troy ounce (ozt) = 31.1035 g

1 gram = 8.98755179×1013 joules (J)

500 grams = 1 Jin (Chinese unit of measurement)

1 avoirdupois ounce (oz) = 28.3495 grams (g)

What is Calorie and Why we count it?

Photo: Getty Images
Photo Getty Images

A calorie is a unit of measurement. Specifically, it is defined as the amount of heat needed to raise the temperature of one gram of water by one degree Celsius.

When the word "calorie" is used in reference to food, people are usually actually talking about the number of kilocalories a specific item has, which is what is listed on nutrition labels.2 One large kilocalorie (kcal) is the equivalent of 1,000 small calories.

The calories we eat supply our bodies with the energy needed to live and stay healthy. Everything we do relies on the energy that comes in the form of calories, whether it is sitting on the couch or running a marathon.

How many calories should people eat every day?

The general range for adult females is 1,600 to 2,400 calories per day. For adult men, it's 2,200 to 3,200 calories daily.4 However, the amount of calories you need depends on a variety of factors such as age and activity level. Using an online calculator can help you determine your individual calorie needs.

READ MORE: 9 Nutrition Tips for the Elderly

What percentage of calories should come from each macronutrient?

The 2020–2025 Dietary Guidelines for Americans recommend that your diet be split according to these percentages:4

10% to 35% protein

45% to 65% carbohydrates

20% to 35% fat

What are basic macronutrients we need everyday?

Macronutrients are the nutrients that provide us with the energy (measured in calories) needed by our bodies for growth, metabolism and other functions. The prefix “macro” means large; macronutrients are needed in large quantities in contrast to micronutrients (vitamins and minerals).

Proteins, fats and carbohydrates make up the group of macronutrients. Let us take a moment to briefly look at each of these macronutrients.

Carbohydrates: These are a major source of energy for our bodies and are stored in our muscles and liver for later use. Foods that contain large amounts of carbohydrates include fruits, grains (rice, oats, barley, etc) and roots (potatoes, yams, carrots, etc). Carbohydrates provide 4 Calories of energy per gram. Check out this post to learn more about carbohydrates.

Photo dietnex
Photo dietnex

Proteins: Our bodies use proteins to grow tissue and muscle, repair organs and to create hormones and enzymes; proteins are also used for energy when carbohydrates are unavailable. Foods that contain high levels of protein include poultry, fish, beans, diary, nuts and legumes. Proteins provide 4 Calories of energy per gram.

Photo Pinterest
Photo Pinterest

Fats: In order to absorb vitamins, our bodies need fats. Foods that contain a high percentage of fat include cooking oils, butter, nuts and cheese. Of the three macronutrients, fats contain the highest number of calories per gram; fats provide 9 Calories of energy per gram.

How Many Calories Per Gram of Fat?

Photo NDTV
Photo NDTV

Each macronutrient (fat, protein and carbohydrates) packs a set number of calories per gram. When it comes to fat, each gram yields 9 calories of energy. So to find out how many calories come from fat, simply multiply the fat grams by 9. If you're looking at a serving of ice cream that contains 15 grams of fat, you'd have:

15 grams × 9 calories/gram = 135 calories

So 15 grams of fat yields 135 calories. Some, but not all, food labels will have this information already displayed right next to the total number of calories per serving.

Percentage of Calories From Fat

Photo lybrate
Photo lybrate

Now that you know how many calories in your favorite food come from fat, perhaps you'd like to know what percentage that is of the food's total calories. In this case, you have to do two simple calculations.

First, divide the number of calories from fat by the total calories. In the case of that ice cream serving, perhaps it has 190 total calories per serving, and you already know that 135 of those come from fat, so you have:

135 ÷ 190 = 0.71

Next, multiply the result you just got by 100 to convert it into a percentage. Continuing the example, this gives you:

0.71 × 100 = 71%

So, 71 percent of the ice cream's calories come from fat.


Remember that nutrition labels list the calories and macronutrient breakdown per serving, not per container, and servings are often much smaller than most people expect.

What are empty calories?

Foods that offer the body very little nutrition, if any, are said to provide empty calories. Soda, chips, and baked desserts all fall into this category.

How Many Calories Per Gram of Protein and Carb?

You can use the same procedure to calculate calories (and calorie percentages) for protein and carbohydrates. But there's a catch: Protein and carbohydrates don't pack 9 calories per gram; they only have 4 calories per gram. So instead of multiplying grams of protein or carbohydrates by 9, you multiply them by 4. For example, if a bowl of cereal has 30 grams of carbohydrates per serving, you'd have:

30 grams × 4 calories/gram = 120 calories

So each serving gets 120 calories from carbohydrates.

Gram to Calorie Conversion Table

Gram measurements converted to calories



1 g

7.7162 kcal

2 g

15.43 kcal

3 g

23.15 kcal

4 g

30.86 kcal

5 g

38.58 kcal

6 g

46.3 kcal

7 g

54.01 kcal

8 g

61.73 kcal

9 g

69.45 kcal

10 g

77.16 kcal

11 g

84.88 kcal

12 g

92.59 kcal

13 g

100.31 kcal

14 g

108.03 kcal

15 g

115.74 kcal

16 g

123.46 kcal

17 g

131.18 kcal

18 g

138.89 kcal

19 g

146.61 kcal

20 g

154.32 kcal

21 g

162.04 kcal

22 g

169.76 kcal

23 g

177.47 kcal

24 g

185.19 kcal

25 g

192.9 kcal

26 g

200.62 kcal

27 g

208.34 kcal

28 g

216.05 kcal

29 g

223.77 kcal

30 g

231.49 kcal

31 g

239.2 kcal

32 g

246.92 kcal

33 g

254.63 kcal

34 g

262.35 kcal

35 g

270.07 kcal

36 g

277.78 kcal

37 g

285.5 kcal

38 g

293.21 kcal

39 g

300.93 kcal

40 g

308.65 kcal

Calculating Your Macronutrients

Now that we have introduced the basics of macronutrients, you can proceed with calculating your macronutrients using the following four (4) steps.

Step 1 – TDEE: Determine your Total Daily Energy Expenditure (TDEE). Check out our post Calories: How Many Do I Need? if you need help determining your TDEE.

Step 2 – Proteins: Estimate your required protein intake by choosing a percentage from the range in the table above (Table 1) and multiplying it by your TDEE. Alternatively, determine how many grams of protein per pound of body weight you need based on your physical activity level. The following chart from recommends protein levels based on physical activity level/lifestyle.

Example Calculation: An adult weighing 150 lbs who exercises recreationally, based on Table 2 above, would need 0.75 grams of protein per pound of body weight.

Daily Protein Intake (in grams) = 0.75 grams per lbs x 150 lbs = 112.5 grams of protein

Next, convert your protein intake from grams to Calories; to do this conversion, multiply your daily protein intake (in grams) by 4.

Example Calculation: Using the result in the previous example

Daily Protein Intake (in Calories) = 112.5 grams of protein x 4 Calories per gram = 450 Calories from protein

Step 3 – Fats: Decide what percentage of your diet will be fat; select a percentage between 15% and 35%. Multiply this percentage by your TDEE to get your fat intake in Calories. Convert this value from Calories to grams by dividing it by 9; 1 gram of fat provides 9 Calories.

Example Calculation: With a TDEE of 2,475 Calories and a desired fat composition of 20%

Daily Fat Intake (in Calories) = 20% x 2,475 Calories = 495 Calories from fat

Daily Fat Intake (in grams) = 495 Calories ÷ 9 Calories per gram = 55 grams of fat

Step 4 – Carbohydrates: Subtract your fat and protein intake values (in Calories) from your TDEE to calculate your required carbohydrate intake.

Example Calculation: Using the values from the examples in steps 2 and 3:

Daily Carbohydrate Intake (in Calories) = TDEE – (Protein Intake + Fat Intake) = 2,475 Calories – (495 + 450) Calories = 1,530 Calories

Convert the carbohydrate intake from Calories to grams by dividing by 4; carbohydrates provide 4 Calories per gram.

Daily Carbohydrate Intake (in grams) = 1,530 Calories ÷ 4 Calories per gram = 382.5 grams

How many calories per day are recommended for weight loss?

Everyone is different, so the number of calories you need to lose weight depends on your sex, age, activity level, and more. Reducing your calorie intake by 500 calories per day is often recommended, but it's better to personalize your calorie goal.13

To do that, you can use a weight loss calculator or consult with a registered dietitian.

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