How your macros are calculated
- Calories: your maintenance needs (Mifflin-St Jeor × activity), adjusted for your goal: −500 kcal to lose fat, +300 kcal to build muscle. Or enter your own target.
- Protein: set by body weight, because that's what research ties protein needs to.
- Fat: a percentage of calories, keeping it at healthy levels for hormones and vitamin absorption.
- Carbs: whatever calories remain. Low-carb and keto styles cap carbs and raise fat instead.
| Style | Protein | Fat | Carbs |
|---|---|---|---|
| Balanced | 1.6 g/kg | 30% of kcal | The rest |
| High protein | 2.2 g/kg | 27% | The rest |
| Low carb | 2.0 g/kg | 45% | ≤ 20% |
| Keto | 1.6 g/kg | ~70% | ≤ 5% (about 20–30 g) |
Why protein matters most
Protein keeps you full, protects muscle while you lose fat and helps you build muscle when you train. Research reviews suggest about 1.6 g per kg of body weight a day is enough for most people building muscle, with up to 2.2 g/kg useful during weight loss. Spreading it across meals, around 25–40 g each, works better than one big serving.
Carbs or fat?
For fat loss, total calories and protein matter far more than the carb-to-fat split. Choose the style you can stick to: people who love bread and fruit do better with balanced macros; people who prefer meat, eggs and cheese may find low-carb easier. Keto is very restrictive and best tried with professional advice.
Making it practical
- Use a food-tracking app for two weeks to learn what your targets look like on a plate.
- Build each meal around a protein source, then add vegetables, a carb portion and some fat.
- Hitting protein and calories within about 10% is plenty; exact grams don't matter.
- Recalculate after losing or gaining 4–5 kg.
Sources
Frequently asked questions
What are macros?
Macronutrients: protein, carbohydrate and fat, the three nutrients that provide calories.
How much protein do I need a day?
About 1.6 g per kg of body weight for most active adults, up to 2.2 g/kg when losing weight. The general minimum for health is 0.8 g/kg.
What is a good macro split for weight loss?
Any split with a calorie deficit and high protein works. A common one is about 30% protein, 40% carbs and 30% fat.
How many carbs are allowed on keto?
Usually 20–50 g of carbohydrate a day, about 5–10% of calories.
Do I have to hit my macros exactly?
No. Getting within about 10% of your calorie and protein targets is enough for good results.
Last updated October 2026 · More health & fitness calculators