Macro Calculator: Your Daily Protein, Carbs, and Fat in Grams

Macros, short for macronutrients, are the three nutrients that supply the calories in food: protein, carbohydrate, and fat. Every calorie you eat comes from one of the three, or from alcohol. A macro calculator converts a daily calorie target into grams of each one.

The conversion uses fixed values. According to the USDA Food and Nutrition Information Center, carbohydrate provides 4 calories per gram, protein provides 4 calories per gram, and fat provides 9 calories per gram. That is why a gram of fat counts for more than twice as much of your calorie budget as a gram of protein or carbohydrate.

Protein

Protein supplies the amino acids your body uses to build and repair tissue, including muscle. It is the macro with the strongest research case for setting in grams per kilogram of body weight, not as a percent of calories.

Carbohydrate

Carbohydrate is the body’s most readily used fuel and the main fuel for hard training. Starches, sugars, and fiber are all carbohydrate. The adult Recommended Dietary Allowance is 130 grams a day.

Fat

Fat carries fat-soluble vitamins, supplies essential fatty acids, and is the most calorie-dense macro. Very low fat intakes are hard to sustain and can leave those needs unmet, which is why guidelines set a lower bound as well as an upper one.

The calculator runs five steps, in order, entirely in your browser. The calorie target comes first, and the macros are that target divided up.

1. It estimates your resting burn. The calculator uses the Mifflin-St Jeor equation (Mifflin et al., American Journal of Clinical Nutrition, 1990), which was derived from measured resting energy expenditure in 498 healthy adults aged 19 to 78. For men it is 10 × weight in kg + 6.25 × height in cm − 5 × age + 5. For women the final term is − 161.
2. It multiplies by your activity level to estimate maintenance calories, from 1.2 for a sedentary week to 1.9 for intense daily exercise. This is the same figure the TDEE calculator (your total daily burn) reports.
3. It adjusts for your goal. Losing subtracts 500 calories a day, capped at 25% of maintenance. Gaining adds 300, capped at 15%. Maintaining changes nothing. These are the same adjustments the calorie calculator (maintenance and a daily target) uses, so the two tools agree.
4. It applies a safety floor. No daily target is displayed below 1,500 calories for men or 1,200 for women. If a deficit would go under that, the target is held at the floor. If the floor leaves no meaningful deficit, the calculator shows no numbers and says why.
5. It splits the calories into macros using the split you chose, then rounds each macro to the whole gram and divides it across three and four meals.

The percentages shown in the result are calculated from the rounded grams, so they always add up to 100.

To calculate your macros, multiply your calorie target by each macro’s share, then divide by that macro’s calories per gram: 4 for protein, 4 for carbohydrate, 9 for fat.

Here is the full calculation for a 35-year-old man who is 5 ft 10 in, weighs 180 lb, exercises three to five days a week, and wants to lose weight on the balanced split.

1. Resting burn: 10 × 81.647 kg + 6.25 × 177.8 cm − 5 × 35 + 5 = 1,757.7 calories.
2. Maintenance: 1,757.7 × 1.55 = 2,724 calories, to the nearest calorie.
3. Target: 2,724 − 500 = 2,224 calories.
4. Protein: 25% of 2,224 is 556 calories. 556 ÷ 4 = 139 grams.
5. Carbohydrate: 45% of 2,224 is 1,001 calories. 1,001 ÷ 4 = 250 grams.
6. Fat: 30% of 2,224 is 667 calories. 667 ÷ 9 = 74 grams.

Enter the same details above and the calculator returns the same 139, 250, and 74 grams. If you only want the resting figure, the BMR calculator (your resting burn) shows that step by itself.

The reference point for any macro split is the Acceptable Macronutrient Distribution Range, or AMDR, set by the National Academies in the Dietary Reference Intakes for macronutrients and reprinted in the Dietary Guidelines for Americans, 2020-2025 (Appendix 1, Table A1-2). For adults 19 and older, the ranges are 10 to 35% of calories from protein, 45 to 65% from carbohydrate, and 20 to 35% from fat.

Only the balanced split sits inside the range for all three macros. The other two step outside it on purpose, and this calculator says so in the result instead of hiding it. The AMDR describes ranges associated with adequate nutrient intake and lower chronic-disease risk across the population. A split outside it is not unsafe by definition, but it is a reason to pay closer attention to food quality and, if you have a medical condition, to check with your physician.

Why Percentages Mislead on Protein

A percentage split ties protein to calories, and calories swing far more than protein needs do. On a 1,400-calorie target, 25% protein is 88 grams. On a 3,400-calorie target, the same 25% is 213 grams. The same person does not need more than twice the protein because their activity went up. That gap is what the protein-first split, and the protein calculator (grams per day and per meal), are built to close.

For weight loss, the calorie deficit does the work and the macros decide what the deficit is made of. No macro split causes fat loss without a deficit, which is why the calories are set first.

Protein is the macro worth protecting. A review in the American Journal of Clinical Nutrition (Leidy et al., 2015) found that tightly controlled feeding studies showed more fat loss and better preservation of lean mass on higher-protein diets than on lower-protein ones during energy restriction, and described 1.2 to 1.6 grams of protein per kilogram a day as the higher-protein range. The review also noted that longer-term studies were mixed, largely because people did not stick to the diets. On a reduced calorie target, hitting that range usually means protein takes a larger share of calories than it does at maintenance.

Fat and carbohydrate are more a matter of preference and adherence. Keeping fat at or above 20% of calories stays inside the AMDR. Carbohydrate takes what is left, and how much you want there often depends on how much you train.

What the Calculator Will Not Do

This calculator will not display a target under 1,200 calories for women or 1,500 for men. Intakes below those levels can make it difficult to meet basic protein, vitamin, and mineral needs and are generally used only under medical supervision. It also will not calculate a deficit below a BMI of 20: choose “Lose” there and it shows maintenance numbers and says so. Below a BMI of 18.5, every result carries a note to talk with a clinician. If you want to see where your BMI sits, the BMI calculator, with its limitations spelled out shows the standard adult categories.

For muscle gain, the calculator adds a modest calorie surplus and makes sure protein is sufficient. This one adds 300 calories a day, capped at 15% of maintenance, because a larger surplus mostly adds fat.

The best single estimate of how much protein helps comes from a meta-analysis of 49 resistance-training studies with 1,863 participants (Morton et al., British Journal of Sports Medicine, 2018). Protein supplementation increased gains in strength and fat-free mass, and intakes above about 1.6 g/kg a day produced no further gain in fat-free mass. On the gain goal, the protein-first split sets protein between 1.4 and 1.9 g/kg depending on how often you train, which brackets that figure.

Carbohydrate matters more here than in a deficit, because it fuels the training that drives the gain. After protein and fat are set, the surplus mostly lands in carbohydrate. Protein supplies the raw material, and resistance training is the signal to use it; a surplus without training is simply a surplus. If you want to lose fat and gain muscle at the same time, the body recomposition calculator (calories and protein) sets calories near maintenance instead.

During weight loss on a GLP-1 medication, the most useful order for setting macros is protein first, in grams from body weight, then fat, then carbohydrate. A percentage split works backwards for this situation: as appetite and calories fall, a fixed percent delivers less protein exactly when preserving muscle matters most.

The source for the range is the 2025 joint advisory on nutritional priorities to support GLP-1 therapy for obesity (Mozaffarian et al., American Journal of Clinical Nutrition), issued by the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and The Obesity Society. It names preserving muscle and bone through resistance training and an appropriate diet as a priority during treatment. Its full text makes three points this calculator is built on:

• The adult RDA for protein is 0.8 g/kg a day, and higher targets, such as 1.2 to 1.6 g/kg a day, have been proposed during active weight reduction.
• For people with obesity, basing the target on actual body weight can significantly overestimate protein requirements, and there is no consensus yet on the best reference weight.
• Prolonged intakes at or above 2 g/kg a day should be avoided.

What the Protein-First Setting Does

1. Protein is set in grams from a reference weight. At a BMI of 25 or below, that is your actual weight. Above 25, it is an adjusted weight: the weight at a BMI of 25 for your height plus 40% of everything above it. With the GLP-1 box ticked, protein is held between 1.2 and 1.6 g/kg of that reference. Without it, the figure is the middle of the range the protein calculator uses for your goal and activity, and never more than 1.9 g/kg.
2. Fat gets 30% of calories, the middle of its 20 to 35% AMDR.
3. Carbohydrate gets every calorie that is left.

The adjusted reference weight is this calculator’s own practical choice, not a figure from the advisory, which says the question is unsettled. Ticking the GLP-1 box never changes, suggests, or refers to a medication amount. It changes a food-protein figure and nothing else.

Appetite on these medications is often low, so the practical side matters as much as the number: eat the protein on the plate first, and consider four smaller meals if three cannot hold the total. For more, read our guides to muscle loss on GLP-1 medications and how many calories to eat on a GLP-1.

Protocol MD prescribes compounded semaglutide and compounded tirzepatide to patients a physician determines are appropriate candidates. Compounded medications are not FDA-approved. The FDA-approved semaglutide and tirzepatide medications carry a boxed warning for thyroid C-cell tumors and are contraindicated in people with a personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2.

The method is the same for women and men. What changes is the size of the calorie budget. At the same height, weight, and age, the Mifflin-St Jeor equation puts a woman’s resting burn 166 calories a day lower, which is 200 to 315 calories of maintenance once the activity multiplier is applied.

A smaller calorie budget is exactly where percentage splits run short on protein, so the protein-first split is worth comparing against any preset. It is also where a 500-calorie deficit is most likely to reach the 1,200-calorie floor, in which case the target is held there or no number is shown. That is the tool working as designed, not an error.

Grams of protein, carbohydrate, and fat in a typical serving of common foods, calculated from USDA FoodData Central values. Brands and preparation vary, so check the label on packaged foods.

Most whole foods are a mix. Lentils count toward protein and carbohydrate, salmon toward protein and fat, and almonds toward all three. Cooking oils are the easiest macro to undercount: one tablespoon of olive oil is 14 grams of fat and about 120 calories.

The result divides each macro evenly across three and four meals. Even is a sensible default, and protein is the macro where the distribution has the most evidence behind it.

The International Society of Sports Nutrition position stand on protein and exercise (Jäger et al., 2017) recommends about 0.25 grams of high-quality protein per kilogram of body weight per meal, or an absolute amount of 20 to 40 grams. If your per-meal protein figure lands well above 40 grams, four meals will be easier than three.

Carbohydrate and fat can move around freely. Many people put more carbohydrate near training and keep fat lower in that meal. A protein-rich snack, such as Greek yogurt or cottage cheese, counts as a meal for this purpose.

A macro calculator is only as accurate as its calorie estimate, and that estimate is a prediction from height, weight, age, and sex. It does not measure you.

In the study that produced it, the Mifflin-St Jeor equation explained 71% of the variation in measured resting energy expenditure, and the older Harris-Benedict equations overestimated measured values by 5%. That still leaves real differences between people of the same size. The activity multiplier adds more uncertainty, because five categories cannot describe every week.

The equation also uses total body weight. Two people at the same weight with very different amounts of muscle get the same estimate, even though the one with more muscle burns more at rest.

The practical answer is to treat the result as a starting point. Follow it for two to four weeks, watch what your weight actually does, and adjust calories by 100 to 200 a day if the trend does not match the goal. The weight loss percentage calculator puts a change in weight in context.

Protocol MD is a physician-guided telehealth practice. A set of macros is one piece of a plan. The rest, including whether any medication is appropriate, depends on your history, your labs, and your goals, and only a licensed physician can make that call after reviewing them.

Protocol MD sells compounded semaglutide and compounded tirzepatide and therefore has a commercial interest in this topic. For patients a physician determines are appropriate candidates, Protocol MD prescribes compounded semaglutide or compounded tirzepatide, prepared by a licensed compounding pharmacy. Compounded medications are not FDA-approved. They are not generic equivalents of, and are not the same product as, the brand-name medications. Nothing in this calculator depends on taking a medication, and the protein-first split is available to anyone.