- Step #1: Calculate Your Basal Metabolic Rate (BMR)
- Step #2: Calculate Your Total Daily Energy Expenditure (TDEE)
- Step #3: Know Your Body Fat Percentage and Lean Mass
- Step #4: Adjust Your Calorie Intake for Weight Loss or Weight Gain
- Step #5: Calculate Your Carbohydrate Intake
- Step #6: Calculate Your Protein Intake
- Step #7: Calculate Your Fat Intake
On the keto diet, knowing how to calculate macros (fat, protein, and carbs) is much more important than counting calories. To enter ketosis, you will need to follow a low-carb, high-fat meal plan so your body can start burning ketones as its primary energy source.
Most people consume roughly 75% of their calories from fat, 20% from protein, and 5% or less from carbohydrates.
These are only rough guidelines. Your specific macros will depend on your body type, activity level, and weight loss objectives.
Use the Perfect Keto calculator to know how to calculate macros
Your basal metabolic rate (BMR) is the number of calories your body needs to support your vital functions (like breathing), without added stress (like exercise)[*]. The more mass you have, the more energy (calories) you need to support daily processes.
While it’s tough to get an exact calculation of basal metabolic rate, you can get really close by using the Harris-Benedict equation below. (If you use the metric system, the Mifflin-St.Jeor formula will be easiest for you.)
- BMR for men = 66 + (6.2 x Your current weight in pounds) + (12.7 x Height in inches) – (6.76 x Age)
- BMR for women = 655.1 + (4.35 x Weight in pounds) + (4.7 x Height in inches) – (4.7 x Age)
Here’s why the equation includes these factors:
- Height and body weight: The more of “you” there is, the more energy you will use. In other words, the greater your body mass, the more calories you will need per day.
- Age: Since muscle mass gradually declines as you go past age 30, BMR decreases over time as well. That’s why this equation factors in age.
- Gender: Since body composition is typically different between men and women, gender plays into the equation.
BMR accounts for the calories needed to support vital processes only — breathing and digesting foods, or processes you need to survive. Your total daily energy expenditure (TDEE) takes into account your activity level and exercise routine. By multiplying your BMR by your level of activity, you get the total amount of calories you will burn per day[*].
To do this, you will multiply your BMR by these numbers (choose the number associated with your level of daily physical activity):
- 1.2: Little to no exercise
- 1.375: Light exercise 1–3 days per week
- 1.55: Moderate exercise 3–5 days per week
- 1.725: Hard exercise 6–7 days per week
- 1.9: Very intense exercise
Exercise can include what you do all day at work,for instance, if you’re on your feet all day as a waiter or lifting heavy boxes.
After selecting your corresponding number, multiply it by the BMR from your calculations in step one. For example, a woman with a BMR of 1500 who does moderate exercise would multiply 1500 by 1.55 to get her total daily calorie expenditure: 2,325.
Measuring your body fat percentage is important for calculating how much lean body mass you have and how much protein you’ll need to maintain muscles. Why? Because muscle burns more calories — even in a sedentary state — than fat[*].
A person with a lower body fat percentage will burn more calories than someone who weighs the same but has a higher body fat percentage.
You can measure body fat in a few different ways:
- DEXA scan: This is the most accurate method but takes the most time and money. It’s a type of X-ray that measures your bone mineral density and can give you a good reading of your body fat percentage.
- Skinfold calipers: This is probably the most popular method. They’re cheaper than a DEXA and most gyms and doctor’s offices will have these. You can even purchase them yourself.
- Body measurements: This involves using a measuring tape to get the width of your neck, hips, and waist to estimate body fat composition. While not the most accurate, it can give you a good idea.
- Visual estimates: If you’re not able to apply the above methods, you can estimate your body fat percentage visually. This means looking at your body and making a guess about how much fat vs. muscle you see. Keep in mind this the least accurate method and will only give you a basic estimation.
Once you know your body fat percentage, you can also determine your lean body mass. For example, if someone weighs 150 pounds and is 25% body fat, they can figure out their body fat in pounds:
150 pounds x 0.25 = 37.5 pounds of body fat.
To get lean body mass, use this equation: 150 pounds – 37.5 pounds of fat = 112.5 pounds of lean body mass.
You will use these numbers to calculate your protein needs. But first, you need to calculate for a caloric deficit or surplus — depending on whether you want to lose or gain weight.
If you’re not looking to change your weight, you can skip this step.
If you want to lose weight, you need to eat at a calorie deficit each day. A reduction of 10–20% of calories is usually a good range to start with for weight or fat loss.
To reduce by 10%, multiply your total TDEE by 0.10, then subtract that amount from your original calorie count. This is the max amount of calories you’ll want to want to consume each day. Free apps like MyFitnessPal are a great way to track your daily caloric intake.
If you want to lose weight at a more rapid rate, feel free to increase the percentage — just know that it’s not recommended to increase your calorie deficit by more than 30% each day long-term.
If you want to gain muscle, you’ll need to eat at a calorie surplus each day. A 5–10% calorie increase is a good range for putting on muscle. Start by multiplying your total calorie expenditure by 0.05, then add that number to your total calorie expenditure. This is your daily calorie count.
The ketogenic diet is a very low-carb diet, where net carbohydrates only make up 5–10% of your total calories. Remember: Net carbs equal your total carb count minus the amount of fiber you consume. For most people, that equates to 20-50 grams per day. To calculate this, you will take:
TDEE x (% of calories) / 4 = Grams of carbs per day, or:
Take your total calories from your TDEE calculated in step 2 (or step 1 if you are maintaining your weight) and multiply it by 0.05 to get your 5% of calories number. Divide the end number by 4 to calculate your carb intake in grams.
Follow the same process to calculate 10% of your calories (take your total calories times 0.10 then divide that by 4 to get grams). These two numbers will be the range in which you want to keep your carb count.
For example, someone with a total caloric intake of 2,000 per day who wants to stay within 5–10% carbs from total calories (2000 x 0.05 or 0.10) would calculate between 100–200 calories from carbs, which is 25–50 grams of carbs per day.
On the keto diet, protein accounts for roughly 20-25% of total calories. While many keto dieters used to think that overeating protein would send your body into gluconeogenesis and raise your blood sugar, that’s not necessarily the case.
Your protein intake depends a lot more on your fitness level and body composition goals. And eating more than 25% of your calories from protein won’t kick you out of keto.
If you’re someone who’s sedentary, a good protein ratio is 0.6-0.8 grams of protein per pound of lean body mass, calculated in step #3.
If you’re moderately or lightly active, stick with 0.8-1.0 grams per pound of lean body mass. A person who wants to gain muscle (or lifts weights) will need to be in the 1.0–1.2 grams per pound of lean body mass range.
Use these ranges to determine a range for your protein needs in grams, then multiply the result by 4 for the same number in calories.
For example, a moderately active female who weighs 150 pounds and has 112.5 pounds of lean body mass will need 90-112.5 grams of protein per day. Then multiply that number by 4 to calculate 360-450 calories from protein per day.
Most experts believe that fat on the keto diet should make up at least 70–80% of your total calorie intake. But this can change a little, depending on your protein intake. To calculate your fat needs, add your protein and carbohydrate percentages together, then subtract from 100.
The end percentage (whatever is leftover) is your fat needs. Be warned: the amount of fat people need to consume to enter ketosis can be surprising.
You will need to eat large amounts of high-fat keto foods, like coconut oil, fatty fish and avocados.
There you go. You’ve just become your own keto calculator. This is all you need to know about how to calculate macros on the ketogenic diet (as well as get an overview of your body mass and goals).
How to Calculate Macros: Ready, Set, Go
Although these formulas can be helpful, there’s no guarantee they are 100% accurate. The goal is to have a range to work with, one that you can refine over time. As time goes on, you will learn which macro guidelines work best for your diet.
As always, the only way to ensure your macros get you into ketosis is to test your ketone levels. To learn how to do this, read this guide on testing your ketone levels.