What macros are — and why they matter
Macronutrients ("macros") are the three nutrients that supply energy: protein, carbohydrate and fat. Your calorie total decides whether you lose or gain weight; your macro split decides how good you feel and whether that weight change is muscle or fat.
Each gram of protein and carbohydrate provides about 4 calories, while fat packs 9 calories per gram. This calculator takes your daily calorie target and divides it into grams of each macro based on the diet style you choose.
Why protein comes first
Protein is the macro most worth getting right. It preserves muscle while you're in a calorie deficit, keeps you full, and has the highest "thermic effect" — your body burns more energy digesting it. A common evidence-based target is 1.6–2.2 g of protein per kilogram of body weight for people who train. If a preset's protein looks low for you, nudge toward a higher-protein style.
Choosing a split
| Style | Protein | Carbs | Fat | Best for |
|---|---|---|---|---|
| Balanced | 30% | 40% | 30% | General health, flexible eating |
| High protein | 40% | 35% | 25% | Fat loss, muscle building |
| Low carb | 40% | 20% | 40% | Appetite control, fewer cravings |
| Keto | 25% | 5% | 70% | Ketogenic diets |
Hitting your numbers
You don't need to be exact to every gram. Aim to land within about 5–10 g of each target most days. A food-tracking app and a kitchen scale make this far easier, especially in the first few weeks while you learn the macro content of your usual meals. Over time you'll be able to eyeball portions.
Build the full picture
Macros sit at the end of the planning chain. If you haven't already, work out your BMR and daily calorie target first, then come back here to split it. Tracking body fat over time will confirm whether your macro plan is building muscle and losing fat as intended.
Helpful tools to track your progress
Track weight and trends over time.
View options →Weigh portions to hit your targets accurately.
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Frequently asked questions
How much protein should I eat per day?
For people who train, 1.6–2.2 g of protein per kilogram of body weight per day is a well-supported range. Choose a higher-protein split if a preset falls short of that.
Do I need to count macros exactly?
No. Landing within about 5–10 grams of each target on most days is plenty. Hitting your protein and overall calories consistently matters more than precision.
Which macro split is best for weight loss?
A higher-protein split tends to work best for fat loss because protein preserves muscle and keeps you full. The best split overall is the one you can sustain.
How many calories are in each macro?
Protein and carbohydrate each provide about 4 calories per gram, and fat provides about 9 calories per gram. Alcohol, not counted here, provides 7.