How to Calculate Protein, Fat and Carb Food Ratios
© Bee Wilder March 9, 2015
Adults under 5 feet tall, babies and children under 12 years of age calculate their ratios differently than adults 5 feet tall and children 12 years and older—see the section below for people under 5 feet tall, babies, and children under 12 years of age.
Caution: Do not translate calculated grams to amounts, quantities, weight, size, etc. of foods you need to consume because it doesn’t work that way.
Use a Nutritional Calculator to Figure Out the Quantities of Foods You Need to Consume in order to meet your calculated protein, fat and carb ratios. Some people use Fitday.com to help with planning this out.
- Consumed ratios do not have to be exact.
- It is very important that your carb ratios are low, but your fat and protein ratios must not be lower than your calculated ratios, except when you are slowly changing over to this program. Also, protein can be a lot higher when you are able to consume at least the lower range of your fat ratios.
Calculations for people 5 feet tall and over.
In order to calculate your daily food intake needed, first you need to calculate how many grams of protein you need to consume in a day to satisfy the body’s requirements. This amount depends upon the person’s “due body weight” (defined below). Please note that babies, children, and people that are 5 feet and under need to calculate their ratios differently—see the directions below.
“Due body weight” in kilograms, is equal to the person’s height in centimetres less 100; height in feet and inches is translated to kilograms, which is noted below.
The daily ratio of proteins, fats, carbs are calculated in grams, not calories, as follows:
- 1 gram of protein per kilogram of “due body weight”
- Fats are calculated by taking each gram of protein multiplied by 2.5 (minimum) to 3.5 (maximum)
- Carbs are calculated by taking each gram of protein multiplied by 0.8 (overweight people should consume lower carbs at 0.5 or 0.3).
- First, translate your height from inches to centimetres:
- Take your height in inches, i.e. 66 inches (5 feet 6 inches tall), and multiply it times 2.54 to get your height in centimetres, i.e. 66 x 2.54 = 167.64 centimetres.
- Next take the amount of centimetres and subtract 100, i.e. 167.54 minus 100 = 67.54, or rounded out to 68, which equals “due body weight.”
- Thus, 68 is the amount of protein grams to consume daily.
- To calculate fats, take 68, which is your “due body weight,” and multiply it times 2.5 to find out the minimum amount of fat grams to consume daily, i.e. 68 x 2.5 = 170 grams of fat. For the maximum amount of fats to consume, take 68 x 3.5 = 238 grams of fat maximum.
- To calculate your daily carb intake, take 68 x 0.8 = 54.4, rounded to 54 grams, or for those that are overweight take 68 x 0.5 = 34 grams or 68 x 0.3 = 20 grams.
Therefore a person 5 feet 6 inches tall needs to consume the following ratios daily:
- 68 grams of protein
- 170 to 238 grams of fats
- 54 grams of carbs
How to calculate ratios for adults under 5 feet tall, babies & children under 12 years old
Note: Ratios are based up on the number of calories needed daily, which are translated into protein, fat and carb gram ratios.
- First, find out how many calories are needed per day:
- Adults: Body Mass Index Calculator.
- Babies & Children: Note: Children over 5 feet tall are calculated the same as adults above, which is by their height in centimetres.
- Determine your child’s weight in kilograms (1 kilogram = 2.2 pounds), i.e. pounds divided by 2.2 = kilograms. Once you know that, calculate the average amount of calories needed: Number of kilograms x calories = daily amount of calories needed.
These calculations are for a normally active child. A child that is much more active needs more calories per day. A reasonable rule of thumb for this extra need is for an active child (defined as an hour per day of sustained physical activity) needs about 1.25 times their calories calculated below. A very active children (defined as more than 90 minutes of sustained physical activity per day) needs 1.5 times their calories calculated below.- Age newborn to 3 months: 100 calories per kilogram per day.
- Age 3 months to 3 years: 90-100 calories per kilogram per day.
- Age 3 years to 8 years: 80-90 calories per kilogram per day.
- Age 8 years to 12 years: 60-80 calories per kilogram per day.
- Age 12 years to 16 years: 45-60 calories per kilogram per day.
- Determine your child’s weight in kilograms (1 kilogram = 2.2 pounds), i.e. pounds divided by 2.2 = kilograms. Once you know that, calculate the average amount of calories needed: Number of kilograms x calories = daily amount of calories needed.
- Split Calories into Protein, Fat and Carbs Calories:
- Protein: Total calories needed per day times 13%, for example 1,500 x 13% = 195 calories.
- Fat: Total calories needed per day times 76%, for example 1,500 x 76% = 1,140 calories.
- Carbs: Total calories needed per day times 11%, for example 1,500 x 11% = 165 calories.
- Translate Calories to Grams:
- Protein calories divided by 4 calories, for example 195 calories (above) divided by 4 = 49 protein grams.
- Fat calories divided by 9 calories, for example 1,140 calories (above) divided by 9 = 127 fat grams.
- Carb calories divided by 4 calories, for example 165 calories (above) divided by 4 = 41 carb grams.
After you write down protein, fat and carbs grams (above) that are needed per day, use a nutritional calculator to determine the amount of foods you need to consume in order to meet your ratios. Do not translate your ratio grams to amounts, i.e. weight or size, because it doesn’t work that way.