Macro Calculator

How it works

Each macronutrient provides a fixed amount of energy per gram:

Protein: 4 kcal/g · Carbohydrate: 4 kcal/g · Fat: 9 kcal/g

We multiply your calories by each percentage and divide by these values. Default splits (protein / carbs / fat):

If you set protein yourself (grams per pound of body weight or percent of calories), the remaining calories are divided between carbs and fat in the goal's ratio.

How these compare with official ranges

The National Academies' Acceptable Macronutrient Distribution Ranges (AMDR) for adults are protein 10–35%, carbohydrate 45–65% and fat 20–35% of calories. Our weight-loss and maintenance splits are higher in protein and lower in carbohydrate than the AMDR — a common approach in fitness nutrition because protein helps preserve muscle and keeps you full — but they sit outside the general-population ranges. If you prefer to stay within the AMDR, choose "Percent of calories" and set protein to 20–30%; the maintain or gain ratios then land carbs and fat near the AMDR.

Low-calorie targets

If your target is below 1,500 calories, you'll see a safety note. Common guidance is not to go below 1,200 kcal/day (women) or 1,500 (men) without medical supervision. Get a safe target from the Calorie Calculator.

Turning grams into meals

Dividing daily macros across three meals and a snack makes them practical. For 150 g protein, 200 g carbs and 67 g fat, each meal might include about 40 g protein (a chicken breast or a cup of Greek yogurt plus eggs), 50–60 g carbs (a cup of rice and a piece of fruit) and 15–20 g fat (a tablespoon of olive oil plus a few nuts), with the snack filling the gap.

Choosing quality sources

Macros say nothing about food quality. For carbohydrates, favor whole grains, legumes, fruit and vegetables, which add fiber and micronutrients. For fat, emphasize unsaturated sources such as olive oil, nuts, seeds and fish, and keep saturated fat below 10% of calories as U.S. dietary guidance recommends. For protein, mix lean meats, fish, dairy, eggs and plant proteins.

Adjusting your macros

Treat your first split as an experiment. If you are often hungry, a little more protein or fiber may help. If workouts feel flat, more carbohydrate around training can help. Keep total calories steady while you adjust, change one thing at a time, and give each change two weeks before judging it.

Tracking tips

Weigh foods for a week or two to calibrate your eye; portion estimates are often off by 20% or more. Remember cooking oils, sauces and drinks, which are easy to miss. Food labels may legally differ from actual content, so aim for consistency rather than perfection.

Worked examples

Example 1: 2,000 kcal, maintain

Protein 30% = 600 kcal ÷ 4 = 150 g; carbs 40% = 800 ÷ 4 = 200 g; fat 30% = 600 ÷ 9 ≈ 67 g.

Example 2: 1,800 kcal, lose

Protein 720 kcal = 180 g; carbs 540 kcal = 135 g; fat 540 kcal = 60 g.

Example 3: 2,800 kcal, gain

Protein 840 kcal = 210 g; carbs 1,260 kcal = 315 g; fat 700 kcal ≈ 78 g.

Limitations

• Splits are common starting points, not prescriptions; individual needs vary.
• Food labels and tracking apps have their own error.
• Fiber, alcohol and micronutrients are not covered.

Who should not rely on this calculator

People with kidney or liver disease, diabetes on insulin or other glucose-lowering drugs, pregnant or breastfeeding people, and anyone with an eating disorder history should set macros with a doctor or registered dietitian.