Macro Calculator (Calories + Macros in Grams)

A macro calculator estimates how many calories, protein, carbs, and fats you should eat per day based on your age, height, weight, activity level, and goal (fat loss, muscle gain, or maintenance). Use your results as a starting point, then adjust slightly based on progress over 2–3 weeks.

Use the calculator above, then read the guide below to understand what your macro numbers mean and how to follow them in real life.

How to Use This Macro Calculator (Best Results)

To get the most accurate targets from any macro calculator, small details matter. Follow these steps:

1. Choose your goal
   Select lose weight (fat loss), maintain, or gain weight (muscle building).
2. Enter accurate measurements
   Use a recent weigh-in and your real height. Even small changes can shift calorie and macro targets.
3. Pick the correct activity level
   Most people overestimate activity. If you have a desk job and train a few times per week, a “light to moderate” option is usually more realistic than “very active.”
4. Decide your macro preference (optional)
   Some people feel better with higher carbs, others prefer higher fats. Preference helps adherence—your consistency matters more than “perfect” ratios.
5. Track for 14 days, then adjust
   Your output is a strong baseline. If weight and measurements are not moving in the direction you want after 2–3 weeks, adjust calories slightly (usually 100–200 calories at a time).

What Are Macronutrients (Macros)?

In nutrition, macronutrients (macros) are the main nutrients your body uses in large amounts for energy and function: protein, carbohydrates, and fats. This calculator focuses on those three.

Micronutrients are vitamins and minerals (like iron, iodine, vitamin A). You need them too, but in much smaller amounts.

Protein: What It Does + Common Sources

Protein supports muscle repair, recovery, and many core body processes. If your goal includes fat loss or muscle gain, protein is usually the macro that matters most for body composition.

Common protein sources

• Chicken, turkey, lean beef
• Fish and seafood
• Eggs and low-fat dairy
• Beans, lentils, tofu, soy
• Nuts and seeds (also higher fat)

Tip: If hunger is a problem during dieting, increasing protein and choosing minimally processed options often helps adherence.

Carbohydrates (Carbs): Fuel for Training and Daily Energy

Carbs include sugars, starches, and fiber. They’re a primary energy source, especially for training, sports performance, and higher-volume workouts. Complex carbs that include fiber are usually more filling and easier to manage for long-term health.

Common carb sources

• Rice, oats, potatoes, whole grains
• Fruits and vegetables
• Beans and legumes

Tip: If workouts feel flat, energy is low, or training performance drops, carbs are often the first place to look.

Fat: Hormones, Satiety, and Long-Lasting Energy

Dietary fats help with hormone function, vitamin absorption, and satiety (feeling satisfied after meals). Fats are also the most calorie-dense macro, so small changes can meaningfully impact total calories.

Common fat sources

• Olive oil, avocado, nuts, seeds
• Fatty fish
• Dairy and whole eggs (in moderation)

Tip: If you enjoy higher-fat meals and can stay consistent, a slightly higher-fat macro split can work well—especially for maintenance.

Calories and Macros: How the Math Works

Your calorie target is estimated from your daily energy needs. Most calculators begin by estimating BMR (basal metabolic rate) and then multiply it by an activity factor to get daily calories. A widely used method is the Mifflin–St Jeor equation, and some calculators also use alternatives that consider lean mass (like Katch–McArdle).

Once calories are estimated, macros are converted into grams using standard calorie values per gram:

• Protein: 4 calories per gram
• Carbs: 4 calories per gram
• Fat: 9 calories per gram

That’s why changing fat by even 10–15g can noticeably change total calories.

Macro Splits by Goal (Fat Loss, Muscle Gain, Maintenance)

There’s no single “perfect” macro ratio for everyone. But most top macro calculator pages use common splits that are easy to follow and adjust.

1) Macros for Weight Loss (Fat Loss)

Most people do well with:

• Higher protein
• Moderate carbs
• Moderate fats

Some calculators use a split like 40/40/20 (carbs/protein/fat) for fat loss as a starting structure, then adjust based on preference.

Practical approach:
Start with a moderate calorie deficit (not extreme). Keep protein consistent, then shift carbs/fats based on what helps you stay consistent.

2) Macros for Muscle Gain (Weight Gain)

For gaining muscle, you generally need:

• A calorie surplus (small to moderate)
• Enough protein for recovery
• Enough carbs to support training performance

A common baseline split used on ranking pages is 40/30/30 (carbs/protein/fat) for gaining and maintenance, with calories increased for gaining.

Practical approach:
Aim for steady progress, not rapid weight gain. Faster isn’t always better.

3) Macros for Maintenance (Stay the Same Weight)

Maintenance macros support your current weight and activity output. Many people choose a balanced split and keep adjustments small.

Practical approach:
If weight trends up or down over a few weeks, adjust by a small amount and re-check.

Example Macros in Common Foods (Quick Reference)

Here’s a simple way to “see” macros in real meals (values vary by brand and serving size):

• Chicken breast (cooked): high protein, low fat
• Eggs: protein + fat
• Rice/oats: mostly carbs
• Avocado/olive oil: mostly fat
• Greek yogurt: protein (often moderate carbs)
• Beans/lentils: carbs + protein

If you want precision, weigh portions

Additional Resources

• USDA Dietary Guidelines for Americans
• National Academy of Sports Medicine Nutrition Guidelines
• Harvard T.H. Chan School of Public Health – The Nutrition Source
• Position Stand: Nutrient Timing by ISSN
• American College of Sports Medicine – Nutrition and Athletic Performance