How to Count Macros: A Beginner's Guide

Updated October 5, 2026 · General information, not medical advice.

Macros (short for macronutrients) are protein, carbohydrate, and fat, the three nutrients that supply your calories. Protein and carbs have 4 calories per gram, and fat has 9 [1]. To count macros, you set a daily calorie target, set a protein target, let carbs and fat fill the rest, then log what you eat.

The 4-4-9 rule

Food labels in the United States use these energy values: 4 calories per gram of protein, 4 per gram of carbohydrate, and 9 per gram of fat [1]. They are rounded averages, so label math is close, not exact.

Quick examples:

30 g of protein = 120 calories
50 g of carbs = 200 calories
20 g of fat = 180 calories

Add them up and that is 500 calories. If your log shows a meal with 30 g protein, 50 g carbs and 20 g fat, you can check it with this math.

Step 1: Set a protein target first

Protein has well-studied sports-nutrition guidance, so it is the easiest target to set first. The International Society of Sports Nutrition (ISSN) says 1.4 to 2.0 grams of protein per kilogram of body weight per day is sufficient for most exercising people who want to build or keep muscle [2]. One kilogram is 2.2 pounds.

Example for an 80 kg (176 lb) person:

Low end: 80 × 1.4 = 112 g per day
High end: 80 × 2.0 = 160 g per day

The same position stand notes that higher intakes, 2.3 to 3.1 g/kg, may help resistance-trained people keep lean mass during periods of eating fewer calories [2]. It also gives a per-meal guide of 0.25 g/kg, or an absolute 20 to 40 g, spread across the day [2].

Pick a number inside the range and stick with it for a few weeks. People with kidney disease or other medical conditions should ask a clinician before raising protein.

Step 2: Set a calorie target

Your calorie target depends on your goal. Eating about what you burn keeps weight steady. Eating more tends to support gaining. Eating less tends to support losing. Online calculators give a starting estimate, but they are estimates.

Use your own trend to adjust. Weigh yourself on the same scale under similar conditions, look at the average over a few weeks, and change calories slowly if the trend does not match your goal. This guide does not promise any result. Bodies differ.

Step 3: Let carbs and fat fill the rest

After protein, split the remaining calories between carbs and fat. There is no single correct split. Many lifters put more carbs around training because they like how it feels, while others prefer more fat for taste and fullness. Both can work.

Worked example for a 2,400 calorie target and 140 g protein:

Protein: 140 × 4 = 560 calories
Remaining: 2,400 − 560 = 1,840 calories
Say you choose 60 g of fat: 60 × 9 = 540 calories
Left for carbs: 1,840 − 540 = 1,300 calories, or 325 g (1,300 ÷ 4)

Fat that is very low can make food less satisfying. If you have a medical reason to limit fat or carbs, follow your clinician's advice.

Logging habits that make it work

Counting only helps if you do it consistently. These habits matter more than perfect precision.

Log before you eat. It is easier to adjust a plate than a day that already happened.
Use a food scale for a week or two. It trains your eye for portions.
Scan barcodes for packaged food, since the label has the numbers.
Save repeat meals. If you eat many of the same foods each week, saving them saves time.
Do not skip the oil, sauces, and drinks. They are easy to forget and add up.
Aim for consistent, not perfect. A day that is a bit off is data, not failure.

Some people find counting stressful. If tracking makes you anxious or controls your choices, take a break and talk to a professional.

Doing this in Liftrung

Liftrung's food log has a database of 16,159 foods and a barcode scanner, and logging is free. It also has AI photo scanning, which is the only paid feature ($29.99 per year after a 3-day trial). Photo estimates are estimates, so check the portion.

Key points

Protein and carbs have 4 calories per gram; fat has 9 [1].
A common evidence-based protein range for lifters is 1.4 to 2.0 g per kg per day [2].
Set protein first, then calories, then split what is left between carbs and fat.
Log consistently and use trends, not single days.
Check with a clinician if you have a medical condition or a history of disordered eating.

Sources

U.S. Code of Federal Regulations, 21 CFR 101.9(c). Nutrition labeling of food: calorie content. https://www.ecfr.gov/current/title-21/section-101.9
Jäger R, et al. International Society of Sports Nutrition position stand: protein and exercise. J Int Soc Sports Nutr, 2017. https://pubmed.ncbi.nlm.nih.gov/28642676/