Depending on how you feel about math, one of the worst parts about the keto diet just might be trying to calculate your keto macros ratio. Even if you have an affinity for numbers, the calculations can be, well, time-consuming. That’s where our keto macro calculator comes in.
The classic keto diet uses a macros ratio of 75% fat to 20% protein to 5% carbohydrates. To maximize your benefits, though, you’ll want to adjust your macros to reach your personalized optimal state of ketosis. That’s where a macro calculator can be an especially handy tool.
The central goal of the keto diet is to shift your body out of the mode in which it relies on glucose from carbohydrates for fuel, and into the mode in which it burns fat as its primary fuel. To do this, you’ll need to stick to a high-fat, moderate-protein, and very, very low-carb diet. This sends your body into a state called ketosis.
When you enter ketosis, your body begins to produce ketones from the dietary fat you take in and to use those as its primary energy source. This can lead to a cascade of health benefits, including weight loss and reduced risk of heart disease and diabetes.
In optimal ketosis, your insulin levels stay balanced and low and your body relies on fat for energy. The exact metrics for optimal ketosis vary from person to person and can be determined by measuring the quantity of ketones circulating in your blood. The threshold for ketosis is around 0.5/mM/dl of blood, and the ideal range is between 1.5 and 3 mM/dl.
You can measure your ketone levels by purchasing urine test strips or a blood-ketone meter—the two most reliable methods—or you can assess whether you’re experiencing the symptoms that typically accompany the onset of ketosis, like loss of appetite.
To remain in ketosis, you need to carefully manage your macro ratios. To help you do that, we’re breaking down the key numbers to keep in mind as you determine and track your carb, protein, and fat intake.
As you already know, keeping your carb intake ultra-low is vital to entering and maintaining ketosis. Experts put the hard upper limit for carbohydrate intake at 50 grams per day. The variable that will impact your carbohydrate needs the most is your activity level. If you only engage in light physical activity, you’ll most likely want to keep your carb intake around 20 grams daily. On the other hand, if you regularly engage in high-intensity physical activities, you can be much more flexible with your carbohydrate limit, remaining in ketosis even while eating around 200 carb grams daily
To enter and stay in ketosis, you’ll also need to pay careful attention to the amount of protein you eat. Again, your activity level will influence the amount of protein you need, as will your lean body mass—your total body weight minus your body fat weight. To learn more about how to use different methods for determining your lean body mass and their relative accuracy, check out this resource. The simplest method, and the one that requires only a calculator, is to use the following formulas:
You need to eat enough protein to keep your organs functioning healthily and to preserve—or add to—your lean muscle mass. If you eat too much, however, your body will convert it to glucose and switch out of ketosis.
A number of variables go into determining your ideal protein intake—that’s why our keto calculator can be such an invaluable tool—but the general recommendation is to consume between 0.68 and 1 gram of protein per pound of lean body mass.
Your daily fat intake depends on how many grams of carbohydrates and protein you need to get the results you’re looking for. Your remaining calories will come completely from fat, and should make up between 65% and 80% of your total caloric intake. The biggest variable here is whether you’re looking to maintain or lose weight, and if you’re looking to lose weight, how much and with how large of a calorie deficit.
Important tip: If you’re having trouble meeting your fat-intake goals through diet alone, supplementing with MCT oil can be a great option for achieving keto success. MCTs, or medium-chain triglycerides, are fatty acids that rapidly convert into ketones.
To use our keto macro calculator, you’ll need to have some information on hand. Some of it is super basic stuff you won’t have to think twice about, but other pieces can get a bit trickier. The easy information you’ll need includes your gender, age, weight, and height. You’ll also input whether your goal is to lose weight or to gain it. Then it gets a bit more complex: determining your activity level and body fat percentage.
It’s crucial that you’re honest and accurate with your assessment of your activity level. If not, your ratios won’t be a good fit for you and your lifestyle. Our keto macro calculator asks you to categorize your activity levels as sedentary, lightly active, moderately active, very active, or athlete/bodybuilder. Here’s some specifics to help you decide which category you fall into.
In the simplest terms, your body fat percentage is the amount of fat on your body compared to everything else (which includes not only your muscle mass, but also your bones, tendons, organs…you get the idea). Men and women have different baseline body fat percentages. Basically, without getting too deep into the science of it, women are predisposed to carry more fat on their bodies than men.
That means a competitive body fat percentage range for male bodybuilders might be as low as 3% to 4%, while for female bodybuilders, the low end is between 8% and 9%. Similarly, a male athlete who’s in superb shape might need to be at around 10% body fat to see popping muscle definition, while a female athlete at a comparable level might get equivalent definition at 18% to 20% body fat. And at the other end of the spectrum, a man carrying 30% body fat will look quite different than a woman carrying 30% body fat.
It’s also important to note that body fat percentages have no bearing on your muscle mass, so any two humans with the same body fat percentage may be totally dissimilar looking depending on how muscular they are.
As with your lean body mass, there are a number of ways to calculate your body fat percentage, each with their own pros and cons. Buying a set of body fat calipers is one of the most affordable and reliable ways to do it. You can buy a set online for around $5 and measure yourself in the privacy of your own home. Calipers do tend to underestimate your percentage by 2% to 3%, though.
You can also use a formula developed by the YMCA that estimates your percentage based on your waist measurement, gender, and weight. This online calculator will even do the number crunching for you! Experts do note that this method tends to overestimate your body fat.
Though both these simple, accessible methods can yield slightly inaccurate results, they can be good starting points and will be close enough to use to calculate your keto macros. You can always opt to invest in a more expensive and more precise body fat test in the future, if it feels worthwhile, and in the meantime, you can progress toward your body composition goals.