Macro Calculator
Protein, carbs and fat in grams, a day and a meal.
The equations were fitted separately for men and women, so they need one of the two. It is the body the formula describes, not an identity.
Most people place themselves a level above where they are. When in doubt, take the lower one: the target is easier to adjust up than to explain away.
Optional
Only if you know it from a measurement. With it the resting rate comes from lean mass (Katch-McArdle) instead of weight, height and age.
From a dietitian's plan, say. The split then starts from this, and only weight is needed — sex, age and height are for estimating calories.
Fill in the fields and the answer appears here.
An estimate from a formula, not a measurement. It does not replace a doctor, a dietitian or a qualified trainer — least of all with a health condition, during pregnancy or breastfeeding, or under 18.
How this was worked out
Fill in the fields and the answer appears here.
Guide: Calories decide the weight, protein decides what it is made of6 min read
Calories decide the weight, protein decides what it is made of
Whether you lose or gain weight is settled by the calorie total. The split between protein, carbohydrate and fat changes something else: how much of what you lose is fat rather than muscle, and how much of what you gain is muscle rather than fat. That is why this calculator starts from calories and then sets protein before anything else.
How the split is made
Protein is set by body weight, not by a percentage: 1.6 g per kilogram to maintain, 1.8 to gain and 2.2 to lose. It goes up in a deficit because that is when the body is most willing to give up muscle, and the research on lean, training people eating less points to the higher end.
Fat is a quarter of the calories, inside the 20% to 35% range the dietary reference intakes consider adequate, and never under 0.8 g per kilogram. The floor matters on small calorie totals: a quarter of very little is less than the body needs for hormones and for absorbing vitamins A, D, E and K. When the floor decides, the page says so.
Carbohydrate takes whatever calories are left. It is the flexible part, the one that fuels hard training, and the one that shrinks first when calories are low. If protein and fat alone reach the total, carbohydrate is held at zero and the page says a plan like that needs a dietitian.
Where the calories come from
From the same equation as the TDEE calculator: Mifflin-St Jeor, or Katch-McArdle when you know your body fat. Losing fat takes 15% off maintenance and gaining muscle adds 10% — the gentler of the two steps the TDEE calculator shows each way, because a macro plan is something you follow for weeks. If you already have a calorie number, from a dietitian for instance, type it in and the split starts from that; only your weight is needed then.
When the total comes out under 1,200 kcal a day for a woman or 1,500 for a man, the page says so beside it. Eating below that needs a professional following along.
Per meal
The day is divided evenly across the number of meals you choose, to give the scale of a plate. Meal timing matters much less than the daily total. The one arrangement with some evidence behind it is protein spread over three or four meals rather than eaten at once.
When grams per kilogram overstate
Protein by total body weight works for most people who train. For someone carrying a lot of body fat it asks for more protein than lean mass needs. Dietitians work from a reference weight in that case, and you can do the same by typing it in as the weight.
Nothing here is sent anywhere: it is worked out in your browser, and what you type is gone when the tab closes.
How we calculate
Macro split (2017)
Protein first: weight × 1.6 g/kg to maintain, 1.8 to gain, 2.2 to lose. Fat: 25% of the calories ÷ 9, never under 0.8 g per kg of weight. Carbohydrate: whatever calories are left ÷ 4
Source: Protein: Jäger R et al. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20; Helms ER et al. Int J Sport Nutr Exerc Metab. 2014;24(2):127-138. Fat: within the Acceptable Macronutrient Distribution Range of 20-35% of energy, Institute of Medicine, Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids; 2005. Energy per gram: the Atwater factors (4, 4 and 9 kcal).
Mifflin-St Jeor (1990)
10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5 for men, − 161 for women
Source: Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241-247.
Katch-McArdle (1996)
370 + 21.6 × lean mass (kg), where lean mass = weight × (1 − body fat)
Source: McArdle WD, Katch FI, Katch VL. Exercise Physiology: Energy, Nutrition, and Human Performance. 4th ed. Williams & Wilkins; 1996.
Activity
Resting rate × the multiplier of the level chosen: sedentary 1.2, lightly active 1.375, moderately active 1.55, very active 1.725, extremely active 1.9. The multipliers are conventions, not measurements, and carry an error of their own.
Source: McArdle WD, Katch FI, Katch VL. Exercise Physiology: Energy, Nutrition, and Human Performance.
Frequently asked questions
How are the macros split?
Protein first, by body weight: 1.6 g per kg to maintain, 1.8 to gain and 2.2 to lose, since protein is what keeps muscle in a deficit. Fat is a quarter of the calories, never under 0.8 g per kg. Carbohydrate is whatever calories are left. The working under the answer shows each step with your numbers.
What calories does it start from?
Your TDEE, from the same equation as the TDEE calculator, adjusted for the goal: 15% less to lose fat, 10% more to gain muscle — the gentler of the two steps each way. If you already have a number, from a dietitian for instance, type it in the optional field and the split starts from that instead.
How many grams of protein per meal?
The page divides the day evenly across the meals you choose, to give the scale: 176 g over four meals is 44 g each. How the day is divided matters far less than the daily total, but spreading protein over three or four meals is the one arrangement with some evidence behind it.
What are the best macros for losing fat?
There is no single best split; the calorie total decides whether weight comes off, and protein decides how much of it is muscle. That is why protein goes up when the goal is to lose, and why the deficit here is 15% rather than something steeper.
Why is my carbohydrate so low, or zero?
Because protein and fat are set first, by weight, and carbohydrate gets the rest. With few calories and a high body weight, protein and fat alone can reach the total. The page says so when it happens: a plan like that needs a dietitian.
Should I use my total weight if I carry a lot of fat?
Grams per kilogram of total weight overstate protein for someone carrying a lot of body fat. Dietitians usually work from a reference weight instead; you can too, by typing that weight in the field.
Is anything I type saved?
No. It is worked out in this tab and gone when you close it. Nothing is sent.