What is the Ketogenic Diet?

The Ketogenic Diet is a diet that focuses on fats being your main source of nutrients. Research has shown that the Keto Diet can help with weight loss and also protect the body from numerous disorders such as Type 2 Diabetes and Cardiovascular diseases.

In order for your body to go into a state of ketosis, the body needs a reduction in carbohydrates and a boost of fats in the diet so the body can create Ketones.

Ketones are the primary source of the Ketogenic Diet and are produced in larger volume when the body is depleted of its regular energy source through carbohydrates, this is known as ketosis.

How Do I Calculate the Keto Diet?

To determine your tailored Keto plan, you will need to first calculate how many calories you need each day to sustain regular body function. This calculation is known as the BMR calculation and once calculated, you will need to factor in the Ketosis Ratio. The Ratio usually follows 70-80% fats, 15-30% protein and 5 – 10% carbohydrates. Protein and carbohydrates per gram equal 4 calories whilst fat per gram equals 9, therefore by dividing the calories for each group by these numbers, you will gain your grams of macronutrient s you will need to consume each day to enter Ketosis and also meet your dietary needs. 

What is BMR?

Basal Metabolic Rate (BMR) is the number of calories the human body burns at a basic function to sustain life. This includes breathing, circulation, cellular processes and production. It’s important to know what is BMR should you want to understand how your body uses its energy. Understanding BMR means you can adjust your nutritional intake for whatever goals you are wanting to achieve.

Why Do People Calculate It?

People calculate BMR so they can understand what calories are required to allow their body to function at a basic rate so they can add on the calories burned through day to day life plus what is burned during working out. At this stage a person will know how many calories they need to eat every day to maintain their current weight, deviating from this figure will cause either to gain weight (calorie surplus) or to lose weight (calorie deficit). Factoring in macronutrients which are protein, carbohydrates and fats, it is a formula to hit the goal which you are aiming for.

An example of this is a BMR of 1800 calories + 700 calories from day to day living and working out equal to 2500 calories per day.

If only consuming 2000 calories, that will put the body in a calorie deficit which will result in losing weight. An estimated figure is that a cut of 3500 kcal a week will lead to a loss of 1 pound of fat per week which is an achievable amount if factoring in regular exercise.

BMR Equation 

Step 1) Using the Mifflin-St- Jeor equation below, by inputting your specific age weight and height, it can generate your BMR without an activity measure in a simple calculation. The measurements are in metric, therefore if you record your measurements in imperial, you will need to convert them to Kg and cm before inputting into the equation.

It is important to remember to calculate the values in the brackets before completing the equation

Mifflin-St Joe Equation

BMR (kcal / day) = (10 x weight (kg)) + (6.25 x height (cm)) – (5 x age (yrs)) + s (kcal/day)

Where is s is +5 for males and -161 for females 


27 year old male who is 1.82m and weighs 97kg

BMR (kcal / day) = (10 x 97 (kg)) + (6.25 x 182 (cm)) – (5 x 27 (yrs)) + 5 (kcal/day)

970 + 1137.5 – 135 + 5 = 1977.5 BMR (kcal/day)

Step 2) To determine your calorie requirements you will need to multiply your answer above by one the multiplication which fits your situation best.

If you are:

  • Sedentary (little or no exercise) : Calorie-Calculation = BMR x 1.2
  • Lightly active (light exercise/sports 1-3 days/week) : Calorie-Calculation = BMR x 1.375
  • Moderatetely active (moderate exercise/sports 3-5 days/week) : Calorie-Calculation = BMR x 1.55
  • Very active (hard exercise/sports 6-7 days a week) : Calorie-Calculation = BMR x 1.725
  • Extra active (very hard exercise/sports & physical job or 2x training) : Calorie-Calculation = BMR x 1.9

1977.5 kcal/day x 1.375 (lightly active) = 2719.1 k/cal to maintain weight

If you are looking to increase or decrease in weight, you will need to alter your total calories. Fewer calories will result in you losing weight and more calories to gain weight.

Step 3) To determine your grams of macronutrients, you will need to split your calories to the ratio explained above. For this example, I will do use 70% fats 20% protein and 10% carbohydrates

Fats –  70% of 2719.1 = 1903.34 kcal

1903.34 / 9 (9 kcal equals 1g of fat) = 211.48g

Protein 20% of 2719.1 = 543.81 kcal 

543.81 / 4 (4 kcal equals 1g of protein) = 135.95g

Carbohydrates 10% of 2719.1 = 271.90 kcal

271.90 / 4 (4 kcal equals 1g of protein) = 67.97g


Using the Ketogenic Calculator will enable you to work out how many calories you should be consuming each day. It also tells you how much of each macronutrient you should consume to remain in ketosis. It is important to remember to adjust your eating should your weight change and grow older. This will ensure you are maintaining your calorific and keto goals.