Calculating your daily macros comes down to three steps: estimate how many calories you burn, decide what percentage goes to protein, carbs, and fat, then convert those percentages into grams. The whole process takes about five minutes with a calculator, and once you’ve done it, you have a personalized daily target for each macronutrient.
Step 1: Estimate Your Daily Calories
Before you split anything into macros, you need a calorie baseline. This starts with your resting metabolic rate, the energy your body burns just to keep you alive. The most widely recommended formula is the Mifflin-St Jeor equation, endorsed by the Academy of Nutrition and Dietetics:
- Men: (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) + 5
- Women: (10 × weight in kg) + (6.25 × height in cm) − (5 × age in years) − 161
If you’re working in pounds and inches, multiply your weight by 0.453 to get kilograms and your height by 2.54 to get centimeters. A 35-year-old woman who weighs 150 pounds (68 kg) and stands 5’6″ (167.6 cm) would calculate: (10 × 68) + (6.25 × 167.6) − (5 × 35) − 161 = 1,394 calories at rest.
That number only covers basic survival. To account for movement, multiply it by an activity factor. The Food and Agriculture Organization defines three tiers:
- Sedentary or lightly active (desk job, occasional walks): 1.4 to 1.69
- Moderately active (regular exercise most days): 1.7 to 1.99
- Vigorously active (hard training daily, physical job): 2.0 to 2.4
Using the example above, that 35-year-old woman with a moderately active lifestyle would multiply 1,394 by roughly 1.7, landing at about 2,370 calories per day. This is her total daily energy expenditure, or maintenance calories. To lose fat, subtract roughly 15% (eating around 2,015 calories). To gain muscle, add roughly 15% (eating around 2,725 calories).
Step 2: Set Your Macro Percentages
The three macronutrients carry different caloric loads. Protein and carbohydrates each provide 4 calories per gram, while fat provides 9 calories per gram. This difference matters when you’re converting percentages to actual food amounts.
Your ideal split depends on your goal. Here are practical starting points:
General Health
The Acceptable Macronutrient Distribution Range for adults is 20 to 35% of calories from fat, with the remainder split between protein and carbs. A common balanced split is 30% protein, 35% carbs, and 35% fat. This works well if you’re not training hard and simply want to eat well.
Fat Loss
Higher protein intake protects lean muscle while you’re eating fewer calories. Research shows that getting about 30% of your calories from protein preserves significantly more muscle mass during a calorie deficit compared to 15%. A solid fat-loss split: 30% protein, 40% carbs, 30% fat. Keeping carbs moderate helps fuel your workouts so training quality doesn’t tank.
Muscle Gain
Building muscle requires a calorie surplus and enough protein to support new tissue, but also enough carbs to train hard. A split of 25 to 30% protein, 55 to 60% carbs, and 15 to 20% fat is well-supported for people focused on hypertrophy. The higher carbohydrate intake maintains training intensity, which is ultimately what drives muscle growth.
Step 3: Convert Percentages to Grams
This is where the math gets concrete. Take the fat-loss example: a 2,015-calorie target with a 30/40/30 split.
- Protein: 2,015 × 0.30 = 605 calories ÷ 4 = 151 grams
- Carbs: 2,015 × 0.40 = 806 calories ÷ 4 = 202 grams
- Fat: 2,015 × 0.30 = 605 calories ÷ 9 = 67 grams
Those gram targets are what you actually track each day. Round to the nearest 5 grams for sanity. Nobody needs to hit 151 grams of protein exactly; 150 is fine.
Cross-Check With Per-Bodyweight Guidelines
Percentage-based splits are a solid starting point, but it helps to verify your numbers against gram-per-kilogram recommendations, especially for protein and carbs.
For protein, the baseline recommendation is 0.8 grams per kilogram of body weight per day, but that’s a minimum for sedentary people. If you strength train, aim for 1.4 to 1.8 grams per kilogram. Endurance athletes do well at 1.2 to 1.4 grams per kilogram. For our 68-kg example, strength training would call for 95 to 122 grams of protein. If the percentage method gives you more than that, the extra protein isn’t harmful and may help with satiety during a cut.
For carbohydrates, recommendations scale with exercise intensity. Light exercise calls for 3 to 5 grams per kilogram, moderate daily exercise (about an hour) calls for 5 to 7 grams per kilogram, and intense training lasting one to three hours per day bumps that up to 6 to 10 grams per kilogram. If your percentage-based carb target falls well below these ranges and you’re training hard, consider raising carbs and trimming fat slightly.
For fat, keep your intake between 20 and 35% of total calories. Dropping below 20% long-term can impair hormone production and reduce absorption of fat-soluble vitamins. Even on aggressive fat-loss diets, staying at or above 20% is a practical floor.
Tracking Accurately
Your macro targets are only useful if your tracking reflects what you actually eat. A food scale is the single most impactful tool here, and the key detail most people miss is that raw and cooked weights are not interchangeable. Meat, rice, and pasta all lose water weight during cooking, which concentrates their calories by volume. Eight ounces of raw chicken breast and eight ounces of cooked chicken breast can differ by hundreds of calories. Whichever way you weigh your food, make sure the database entry you select matches: raw if you weighed it raw, cooked if you weighed it cooked.
Fiber is worth tracking within your carb count. Current guidelines recommend 14 grams of fiber per 1,000 calories you eat. On a 2,000-calorie diet, that’s about 28 grams. You don’t need a separate macro target for it, but if your fiber is consistently low, your carb sources are probably too refined.
How to Handle Alcohol
Alcohol provides 7 calories per gram but doesn’t fit neatly into protein, carbs, or fat. Since most tracking apps don’t have a separate alcohol macro, the simplest workaround is to “borrow” from your carb or fat budget. Divide the total calories in the drink by 4 and log it as carbs, or divide by 9 and log it as fat. A 132-calorie glass of wine, for example, counts as either 33 grams of carbs or 15 grams of fat. Use the formula rather than the nutrition label, because labels on alcoholic beverages often undercount or omit calories from the alcohol itself.
Adjusting Over Time
Your initial macro calculation is an educated estimate, not a permanent prescription. Track consistently for two to three weeks, then evaluate. If you’re trying to lose fat and the scale hasn’t budged, drop your calories by 100 to 200 per day, pulling primarily from carbs or fat while keeping protein stable. If you’re trying to gain weight and aren’t gaining, add 100 to 200 calories, mostly from carbs to support training performance.
Recalculate from scratch when your body weight changes by more than 10 pounds, your activity level shifts significantly, or you switch goals entirely. The formulas don’t expire, but the inputs change as you do.