ProteinMacro Calculator
Your daily protein, fat and carbohydrate targets in grams, from your body weight, activity level and goal. The reasoning behind each number is shown alongside it — including why protein comes from your weight rather than from a percentage.
| Macro | Grams | kcal | g/kg |
|---|---|---|---|
| Protein | 160 | 640 | 2 |
| Fat | 73 | 657 | 0.9 |
| Carbs | 262 | 1049 | 3.3 |
- BMR (Mifflin)
- 1,780 kcal
- Projected
- 0.8 lb/wk loss
How this calculator allocates your macros
Most macro calculators hand you a percentage split — 40/30/30, 50/25/25 — and divide your calories by it. That is easy to compute and subtly wrong, because it makes your protein intake a function of your calorie target rather than of your body.
The consequence is backwards. Take a 100 kg person on a 40/30/30 split: at 2,000 calories they get 200 g of protein, but cut them to 1,500 and the same split yields 150 g. Their protein requirement did not fall — it rose, because a deeper deficit puts more muscle at risk. This calculator allocates in a different order:
- 1Protein, from body weightSet from your weight and goal at 1.2–2.4 g/kg, using the same evidence-based ranges as the protein calculator. It does not move when your calories do.
- 2Fat, from a floor in gramsAt least 0.5 g/kg, because very low fat intake impairs sex-hormone production and fat-soluble vitamin absorption regardless of what percentage of calories it represents.
- 3Carbohydrate, from what remainsWhatever calories are left after protein and fat. Carbohydrate is the most flexible macro — it fuels training but has no strict minimum requirement.
Keto inverts steps two and three: carbohydrate is pinned to a 25 g ceiling and fat absorbs the remaining calories. Protein still comes from body weight — the common advice to keep protein low on keto is not well supported for most people.
Calorie targets by goal
| Goal | vs TDEE | What it is for |
|---|---|---|
| Aggressive fat loss | -25% | Fastest sustainable loss. Hardest to adhere to and the most muscle at risk, so protein is highest here. |
| Fat loss | -15% | A moderate deficit most people can hold for months rather than weeks. |
| Body recomposition | -5% | Near maintenance with high protein and resistance training — lose fat and gain muscle slowly, at once. |
| Maintain | — | Hold current weight while supporting training and recovery. |
| Lean bulk | +10% | A small surplus that adds muscle with minimal fat. The default choice for gaining. |
| Bulk | +20% | A larger surplus for faster gain, accepting more fat alongside it. |
Activity multipliers
Your BMR is multiplied by one of these to estimate total daily energy expenditure. Most people overestimate here — “moderately active” means genuine training three to five times a week, not a busy schedule.
| Level | Multiplier | Means |
|---|---|---|
| Sedentary | ×1.2 | Desk job, little or no exercise |
| Lightly active | ×1.375 | Light exercise 1–3 days a week |
| Moderately active | ×1.55 | Moderate exercise 3–5 days a week |
| Very active | ×1.725 | Hard exercise 6–7 days a week |
| Athlete | ×1.9 | Twice-daily training or physical job plus training |
Splits
Balanced
Even split. Suits most people and most training.
High protein
Maximum protein, moderate fat, carbs fill the rest.
Low carb
Higher fat, reduced carbohydrate, without full ketosis.
Keto
Carbohydrate pinned to 25 g; fat takes the remaining calories.
Frequently asked questions
- How do I calculate my macros?
- Start with your maintenance calories (TDEE), then adjust for your goal — typically a 15–25% deficit to lose fat or a 10–20% surplus to gain. Then set protein from your body weight (1.6–2.4 g/kg depending on goal), set fat at a floor of at least 0.5 g/kg, and fill the remaining calories with carbohydrate. Setting protein from body weight rather than from a percentage is the important part.
- What is the best macro split for weight loss?
- There is no single best split, but the protein figure matters far more than the ratio. For fat loss, aim for 1.8–2.4 g of protein per kg of body weight, keep fat at or above 0.5 g/kg, and let carbohydrate take whatever calories are left. That commonly lands near 35–40% protein, 25–30% fat and 30–40% carbohydrate — but the grams are what you should track, not the percentages.
- Why do percentage-based macro splits go wrong?
- Because they scale protein with your calorie target instead of your body. A 100 kg person on a 40/30/30 split eating 1,800 calories gets 180 g of protein; drop them to 1,400 calories and the same split gives 140 g — less protein at exactly the point where a deeper deficit puts more muscle at risk. Anchoring protein to body weight avoids that entirely.
- How many calories should I eat to lose weight?
- A 15–25% deficit from your TDEE for most people, which works out to roughly 0.5–1% of body weight lost per week. Larger deficits are not proportionally better: they cost more muscle, are harder to sustain, and adherence beats aggression over any timeframe that matters. Never set a target below your BMR.
- What are keto macros?
- Carbohydrate pinned to roughly 20–30 g per day, protein set from body weight, and fat taking all remaining calories — usually 60–75% of intake. Note that protein does not need to be low on keto; the common advice to restrict it is largely unfounded for most people.
- Should I use Mifflin-St Jeor or Katch-McArdle?
- Mifflin-St Jeor if you do not know your body fat percentage — it is the best-validated predictive equation for the general population. Katch-McArdle if you do know it, because it works from lean mass and so is more accurate at either extreme of body composition. A guessed body fat figure makes Katch-McArdle worse, not better.
Estimates, not measurements. Every BMR equation is a population-level prediction and individuals vary by roughly ±10%. Treat the output as a starting point, then adjust based on how your weight actually moves over two to three weeks.