How to Calculate Macros: Formula and Examples

What is the macro formula?

The macro formula is: grams = daily calories × share of calories ÷ calories per gram. Macros, short for macronutrients, are the three nutrients that supply most of your energy: protein, carbohydrate and fat.

Protein and carbohydrate each provide 4 calories per gram, and fat provides 9. Alcohol, which is not counted as a macro in these plans, provides 7. So 30% of a 2,000-calorie day from fat is 2,000 × 0.30 ÷ 9 = 67 grams, while 30% from protein is 2,000 × 0.30 ÷ 4 = 150 grams. The same share gives far fewer grams of fat because each gram holds more than twice the energy.

How do you calculate your macros step by step?

Work out your calorie target, choose a split, then convert each share to grams. Here is the process, using a 40-year-old man who is 5 feet 10 inches tall, weighs 200 pounds and exercises 1 to 3 times a week, aiming to lose 1 pound a week.

• Find maintenance calories. His BMR from the Mifflin-St Jeor equation is 1,823 calories, and 1,823 × 1.375 for light activity gives a TDEE of 2,507 calories.
• Apply your goal. A 500-calorie daily deficit gives a target of 2,007 calories.
• Choose a split. A balanced split is 20% protein, 50% carbohydrate and 30% fat.
• Protein: 2,007 × 0.20 ÷ 4 = 100 grams.
• Carbohydrate: 2,007 × 0.50 ÷ 4 = 251 grams.
• Fat: 2,007 × 0.30 ÷ 9 = 67 grams.

What macro split should you choose?

Any split that stays near the National Academies' Acceptable Macronutrient Distribution Ranges (AMDRs) and that you can stick with is reasonable. The AMDRs are 10% to 35% of calories from protein, 45% to 65% from carbohydrate and 20% to 35% from fat for adults.

The table shows what our macro calculator returns for each plan at 2,007 calories, the man's weight-loss target. The low-carb and high-protein plans put carbohydrate at 35% and 40%, below the 45% floor of the AMDR. That does not make them unsafe for most healthy adults, but they sit outside the reference range, so it helps to choose them on purpose. People with diabetes or kidney disease should discuss carbohydrate and protein targets with a clinician.

What is the best macro formula for weight loss?

For weight loss, set calories first, protein by body weight second, fat as a share of calories third, and give whatever remains to carbohydrate. Calories determine how much weight you lose, and protein helps keep muscle while you lose it, so those two come before the rest.

Worked example: a 35-year-old woman who is 5 feet 5 inches and 160 pounds (72.6 kg) with light activity has a target of 1,455 calories for about 1 pound a week. The Dietary Guidelines range for protein is 1.2 to 1.6 g/kg, so she starts at 1.2 g/kg, or 87 grams, which is 348 calories. Fat at 30% of calories is 49 grams, which is 441 calories. That leaves 666 calories, or about 167 grams of carbohydrate.

Her split comes to about 24% protein, 46% carbohydrate and 30% fat, all inside the AMDRs. By comparison, the macro calculator's default balanced split for the same 1,455 calories is 73 grams of protein, 182 grams of carbs and 49 grams of fat. See how much protein you need for choosing a protein figure, and how many calories to eat to lose weight for setting the calorie target and safe minimums.

What's my macro breakdown right now?

To find your current breakdown, log what you eat, convert each macro to calories, and divide by the day's total. A food label or tracking app gives you grams; multiply protein and carbohydrate by 4 and fat by 9.

Example: a day with 110 grams of protein, 200 grams of carbohydrate and 60 grams of fat comes to 440 + 800 + 540 = 1,780 calories. That is about 25% protein, 45% carbohydrate and 30% fat. Log a few typical days, including a weekend day, because one day rarely represents how you eat.

How many grams of carbs and fat should you eat?

Carbohydrate should usually be 45% to 65% of calories and fat 20% to 35%, which for a 1,955-calorie day means 220 to 318 grams of carbs and 43 to 76 grams of fat. Those figures come from our carbohydrate calculator and fat intake calculator for the 160-pound woman at maintenance.

A few other reference points help. The National Academies set the carbohydrate RDA at 130 grams a day for adults, based on the brain's glucose needs. The low-carb plan at her 1,455-calorie target gives 127 grams, just under that figure, which shows how quickly a low share of a small calorie budget falls short. The adequate intake for fiber is 14 grams per 1,000 calories.

For fat, the 2025–2030 Dietary Guidelines keep the limit on saturated fat at no more than 10% of calories, which is under 22 grams on a 1,955-calorie day. Our macro calculator also shows added sugar under 10% of calories, the cap in earlier editions. The current edition is stricter, so treat that number as an upper bound rather than an allowance.

Does hitting your macros matter more than calories?

No. For weight change, total calories matter most, and macros mainly affect how full you feel, how much muscle you keep and overall diet quality. Two plans with the same calories should produce similar weight loss, so pick the split that keeps you full and that you can follow.

Close is good enough. Getting within a few grams of a target each day is rarely necessary, and an average over the week is a more useful measure. Recalculate after losing about 10 pounds, since your TDEE falls as your weight does. To check your starting number, see TDEE vs BMR or use the protein calculator for a body-weight target. If tracking food makes you anxious or you have a history of an eating disorder, skip macro counting and work with a clinician.