Macro Calculator
Split a daily calorie target into grams of protein, carbs, and fat based on your goal.
How the macro split works
Macronutrients — protein, carbohydrate, and fat — are where all your calories come from. Protein and carbohydrate each supply about 4 calories per gram, while fat supplies about 9. This calculator takes your daily calorie target, applies the percentage split you choose, and converts each slice into grams using those energy values.
Start from a calorie number that matches your goal — our TDEE calculator estimates it — then pick a split. A balanced 30/40/30 works for most people. If you're leaning out or building muscle, a higher-protein preset helps preserve lean tissue and keeps you fuller. Endurance athletes often do better with more carbohydrate to fuel long sessions.
Which macro matters most
For body composition, protein and total calories do the heavy lifting. Getting enough protein — commonly 1.6 to 2.2 grams per kilogram of body weight for active adults — supports muscle whether you're losing or gaining. Carbohydrate and fat can then flex around your training, digestion, and food preferences. There is no single "correct" ratio; the best split is the one you can follow consistently while hitting your protein and calorie goals.
Treat the grams as daily targets to approach, not exact quotas for every meal. Consistency over weeks beats precision on any single day.
Energy values (4 kcal/g protein and carbohydrate, 9 kcal/g fat) are the standard Atwater factors. Protein ranges reflect sports-nutrition position stands; see NIH dietary guidance.
Frequently asked questions
What are macros?
Macros, short for macronutrients, are the three nutrients that supply energy: protein, carbohydrate, and fat. Protein and carbs provide about 4 calories per gram and fat about 9, so splitting a calorie target into grams tells you roughly what to eat.
What is a good macro split?
A balanced 30% protein / 40% carbs / 30% fat split works well for most goals. Higher protein suits fat loss and muscle gain, lower carb suits some people managing appetite, and higher carb suits endurance training. This tool includes presets for each.
How much protein do I need?
For active adults, roughly 1.6 to 2.2 grams of protein per kilogram of body weight per day supports muscle. The right calorie total and split will usually land you in a sensible range; adjust the preset if your protein target falls short.
Do I need to hit my macros exactly?
No. Aim to get close over the day and week rather than chasing perfect numbers at every meal. Protein and total calories matter most; carbs and fat can flex around your preferences and training.