How to Calculate Macros on the Keto Diet

Getting the right amount of macronutrients is necessary in order for you to get into ketosis.

Sandwich with a healthy filling and a tape measure

How do you calculate your keto macros? But first off, let’s review what keto diet and micronutrients are.

The keto diet, which was originally developed as a treatment for people with epilepsy, has become extremely popular nowadays among people wanting to lose weight and live a healthier lifestyle. Aside from being a great aid in weight-loss, the keto diet is also believed to reduce seizures, lower risk of cancer, improve heart health, protect brain function, and reduce acne.

The Keto Diet

The goal of the keto diet is to turn your body into a fat-burning machine by using ketones, a type of acid produced by the liver when it breaks down fat. Basically, the body’s main source of fuel is glucose, a byproduct of carbohydrates. However, it can shift into using ketones as fuel for the body when there is not enough glucose available. This metabolic state is called ketosis, a natural state of the body when it is completely fueled by fat. This occurs when carbohydrate intake is low. This is why the standard ketogenic diet or SKD contains 75% fat, 20% protein, and only 5% carbs.

The keto diet is clearly contrary to the standard diet recommended by the U.S. Dietary Guidelines, which consists of 45-65% carbohydrates, 20-35% fat, and 10-35% protein. But the thing is, the keto diet aims to radically change how the body uses these macronutrients by entering into ketosis and using ketones instead of glucose. The standard diet, on the other hand, only reinforces the way the body already makes and uses food for energy.


What are Macros?

Macros is a shortened term for macronutrients. These are nutrients needed in large amounts in order for the body to maintain its functions. The three primary macronutrients are carbohydrates, proteins, and fats.

Getting the right amount of these keto macros is necessary in order for you to get into ketosis. For most people on a keto diet, their calorie intake consists of 75% fat, 20% protein, and 5% carbs. However, for maximum efficiency, your specific macros will have to depend on your gender, age, height, weight, activity level, body fat percentage, and weight loss objectives.

So how do you calculate these macros in order to get the right amount of each on your keto diet? The easiest way is to use a keto calculator. There are a lot of websites on the Internet that have this. There are also keto calculator apps that you can download for free from your mobile phone’s app store. However, if you want to manually calculate your keto macros, here’s how:

Calculate Your Basal Metabolic Rate (BMR)

It is important that you know your BMR because it will show you the number of calories you burn when you are at rest. Basal metabolic rate or BMR is the minimum number of calories your body needs to perform basic, life-sustaining functions, such as breathing, circulation, nutrient processing, and cell production. The more mass you have, the more calories you need to support your body’s basic functions.

Getting an exact BMR can be quite tough, but one popular way to get a close estimate is by using the Harris-Benedict equation. This takes into account a person’s gender, weight, height, and age.

BMR formula for women: BMR = 655 + (9.6 × weight in kg) + (1.8 × height in cm) – (4.7 × age in years)

BMR formula for men: BMR = 66 + (13.7 × weight in kg) + (5 × height in cm) – (6.8 × age in years)


Alice is 25 years old, stands at 160 centimeters, and weighs 60 kilograms.

BMR = 655 + (9.6 x 60) + (1.8 x 160) – (4.7 x 25)

= 655 + 576 + 288 – 117.5

= 1, 519 – 117.5

= 1, 401.5

Therefore, Alice’s BMR is 1, 401.5 per day.

Gender, height, weight, and age are included in the equation because of the following reasons:

  • Gender is considered because body composition between men and women are basically different.
  • Height and weight are included in the equation because the more body mass you have, the more energy or calories will have to use.
  • Age is included in the formula because lean body mass and BMR decrease as we age.

Calculate Your Total Daily Energy Expenditure (TDEE)

Your total daily energy expenditure (TDEE) is calculated by factoring in your BMR and your activity level.  By multiplying your BMR by your activity level, you get the total amount of calories you will burn per day. TDEE includes all the calories or energy you burn when you are exercising, working, sleeping, or eating.

To get your TDEE, multiply your BMR by the number corresponding to your level of physical activity.

TDEE formula for women:

TDEE = BMR x activity level

1.1: Sedentary (little to no exercise)

1.275: Lightly Active (light exercise 1-3 days per week)

1.35: Moderately Active (moderate exercise 3-5 days per week)

1.525: Very Active (hard exercise 6-7 days per week)

TDEE formula for men:

TDEE = BMR x activity level

1.2: Sedentary (little to no exercise)

1.375: Lightly Active (light exercise 1 to 3 days in a week)

1.55: Moderately Active (moderate exercise 3 to 5 days in a week)

1.725: Very Active (hard exercise 6 to 7 days in a week)

1.9: Extremely Active (very intense exercise/training twice in a day)

The term exercise is not restricted to usual exercises such as running, jogging, walking, cycling, or swimming. Doing something physically demanding in a job will also be considered as a form of exercise.

After picking the most appropriate number for you, simply multiply it by your BMR. For example, as mentioned above, Alice’s BMR is 1, 401.5. She is sedentary, having little to no exercise (1.1). So:

TDEE = BMR x activity level

= 1, 401.5 x 1.1

= 1, 541.65

Therefore, Alice has a total daily energy expenditure of 1, 541.65 per day.

Know Your Body Fat Percentage and Lean Mass

It is important that you know your body fat percentage and lean body mass percentage because you have to know how much protein you’ll need to maintain your muscles. For example, since most people go on a keto diet to lose weight, this will help them calculate the amount of protein they need to adequately lose weight without losing excess muscle.

There are different ways to measure body fat. Here are some:

Skinfold calipers

These have been used for over 50 years to estimate body fat, and they might be the most recommended method. They measure your subcutaneous fat or the fat underneath your skin.They are usually used in body locations such as, triceps, abdomen, or thighs.  They are affordable and you can buy one for yourself.

Body circumference measurements

In this method, circumferences of the neck, waist, and hips are used to estimate your body fat percentage. It is very easy to do and also very affordable because you only need a measuring tape. However, this is not the most accurate method. Nonetheless, it can give you a good idea.

Dual-Energy X-ray Absorptiometry (DXA)

A DXA scan uses two different energies to estimate your body fat percentage. While this is the most accurate, this is also the most expensive. Moreover, it’s often unavailable to the general population.

After knowing your body fat percentage, you can now easily calculate your lean body mass. For example, if Alice weighs 132 pounds and 25 % of her body is composed of fat, the equation would be:

132 pounds x . 25 = 33 pounds of body fat

To get her lean body mass, simply subtract her weight with the pounds of fat. So,

132 pounds – 33 pounds of body fat = 99 pounds of lean body mass

These numbers are going to be helpful when you calculate your protein needs.

Adjust Your Calorie Intake: Deficit, Surplus, or Maintenance

Typically, if you want to lose weight or fat, you need to have a deficit in calories. It means you have to eat below your TDEE. Most people work in a range of 10% to 20% deficit. This is what is recommended for starters because going on a 20-30% range will make you fight hunger. Additionally, it is not suggested that you go beyond 30%, because doing so can result in metabolic damage in the long run.

Let’s say, Alice want a 15% reduction. First, she has to multiply her TDEE by .15. Then, she has to subtract that result from her original calorie count or TDEE. For example:

1, 541.65 x .15 =  231.2475

1, 541.65 – 231.2475 = 1, 310.4025

Therefore, Alice’s maximum calorie intake every day should now be at 1, 310.4025 per day.

Now, if you want to gain muscle, you need to create a surplus. It means eating above your TDEE. If you want to put on lean mass, then you need extra calories. An increase of 5% to 10% in your calorie intake is recommended. However,be careful not to go beyond 10% as this can result to excess weight gain.

Let’s say Alice wants to increase her calorie intake by 10%, then she has to multiply her TDEE by .10. Then, she has to add that number to her TDEE.

For example:

1, 541.65 x .10 =  154.165

1, 541.65 + 154.165 = 1, 695.815

Therefore, Alice shall now have a maximum calorie intake of 1, 695.815 per day.

If you neither want to lose weight or put on lean mass, you can keep eating equal to your needs. This is called “maintenance”. For example, if Alice has a TDEE of 1, 541.65, she can just stick to this calorie intake to keep her weight steady.

Calculate Your Carbohydrate Intake

The keto diet is very low in carbs. The calorie percentage allotted for net carbs should be at least 5% but not more than 10%. Net carbs are the total amount of carbs minus the fiber. The body makes glucose only from net carbs. Therefore, fiber has no effect on your body’s glucose level. For example, some food like avocado has more fiber in them than actual carbs. As a matter of fact, one-half of a medium avocado only contains 2 grams of net carbs. Feel free to load up on food like this. Instead of looking at the total carbs, it is best to look at the net carbs.

The recommended daily intake of net carbs is around 20 grams per day. The maximum intake is 30 grams, and you should keep in mind that you should not go beyond this amount. Doing so will kick you out of ketosis, and you don’t want that.

Learn to calculate how much carbs you should consume by taking a look at the example below.

Alice wants to work on her “maintenance” calorie intake which is 1, 541.65. She also only wants 5% of carbs on her diet.


carbs per day = TDEE x (% of calories) / 4 = grams of carbs per day

Carbs per day = 1, 541.65 x .05 = 77.0825 / 4

= 19.27

Therefore, Alice has to consume not more than 19.27 grams of carbs per day.

Calculate Your Protein Intake

On a keto diet, 20 to 25% of your calories should come from protein.

If you are someone who is sedentary, it is recommended that you have 0.6 to 0.8 gram of protein per pound of lean body mass. For those who are active, the recommendation is between 0.8 and 1.0 grams of protein per pound of lean body mass. Finally, for those who want to gain muscle, it is recommended that you consume 1.0 to 1.2 grams of protein per pound of lean body mass. Consuming 1.2 grams is the maximum protein intake and one should not go beyond this.

To determine your protein needs in grams, use the ranges above as your guide. For example:

Alice is a sedentary female who weighs 132 pounds and has 99 pounds of lean body mass. Since she is sedentary, she should only have 0.6 gram to 0.8 gram of protein per pound of her lean body mass.

To get the range of her recommended intake of protein per day, start by multiplying 0.6 by 99. That would be 59.4. Next, multiply this number by 4. The answer would be 237.6. This is Alice’s minimum daily protein intake.

To get the maximum daily protein intake, follow the same calculation above:

0.8 x 99 = 79.2

79.2 x 4 = 316.8

Therefore, Alice should have 237.6 to 316.8 grams of protein per day.

Calculate Your Fat Intake

Fat has the highest calorie percentage in the keto diet. Basically, it is 70%-80% of your total calories. In order to find out the percentage of fat that you should consume per day, simply add your protein and carbohydrate percentages. Whatever is left would be the percentage of calories allotted for fat.

Here is an example using Alice’s data:

19.27 (carbs) + 316.8 (protein) = 336.07 combined calories

336.07 is 21.80% of Alice’s TDEE which is 1, 541.65. So, 100% – 21.80% = 78.20%. Therefore, 78.20% or 1, 205.58 of Alice’s daily calorie intale should come from fat.

To know how many calories you are taking in, remember that protein and carbohydrates contain 4 calories per gram. Fat, on the other hand, contains 9 calories per gram.

So, to convert 1, 205.58 (fat calories) into grams, let’s divide it by 9.

1, 205.58 / 9 = 133.95 grams

Therefore, Alice should consume 133.95 grams of fat or 1, 205.58 fat calories.

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