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Macro calculator: protein, carbs and fat targets
Turn your calorie goal into a practical daily target — grams of protein, carbohydrate and fat — based on your stats, activity level and what you're trying to achieve.
Macro calculator
Your result
112g
Protein · 27%
202g
Carbs · 48%
47g
Fat · 25%
Protein is set first at 1.8 g per kg of body weight (62 kg), fat is fixed at 25% of total calories, and carbohydrate fills the rest of your calorie target.
About this tool
What macro targets do and who needs them
"Macros" is short for macronutrients — protein, carbohydrate and fat, the three nutrients that make up the calories in food. Calorie count tells you how much to eat; macros tell you what to eat it as.
This calculator runs the full chain in one step: it calculates your BMR, scales it to TDEE using your activity level, adjusts the calorie target for your goal, then splits the result into grams of protein, carbs and fat.
Step by step
How to use the macro calculator
- 1
Enter your stats
Sex, age, height and weight — the same inputs used for BMR.
- 2
Pick your activity level and goal
Choose lose, maintain or build, and how active your typical week is.
- 3
Choose a protein target
Standard (1.8 g/kg) for general goals, higher (2.2 g/kg) if you train with weights regularly.
- 4
Select Calculate macros
Your daily calorie target and the protein, carb and fat split in grams appear instantly.
Methodology
How the split is calculated
- Calculate BMR (Mifflin-St Jeor) and TDEE (BMR × activity multiplier).
- Adjust calories for your goal: −20% to lose, unchanged to maintain, +15% to build.
- Set protein at 1.8 or 2.2 g per kg of body weight (4 calories per gram).
- Set fat at 25% of total calories (9 calories per gram).
- Fill the remaining calories with carbohydrate (4 calories per gram).
Worked example
Example calculation
A 28-year-old woman, 165 cm, 62 kg, moderately active, aiming to lose weight: TDEE ≈ 2,065 calories, minus 20% ≈ 1,652 calories. Protein at 1.8 g/kg = 112g (448 kcal). Fat at 25% = 46g (413 kcal). Remaining 791 kcal ÷ 4 ≈ 198g carbohydrate.
Watch out for
Common mistakes
- Cutting calories too aggressively. A deficit much larger than 20–25% makes it harder to preserve muscle and is difficult to sustain.
- Under-eating protein in a deficit. Protein needs go up, not down, when calories are reduced — it's the macro most responsible for preserving muscle.
- Treating fat as the macro to cut to zero. Very low fat intake can disrupt hormone production; the 25% floor used here protects against that.
Be aware
Assumptions and limitations
- Built on the same BMR/TDEE assumptions described on those calculator pages.
- Fixed deficit (−20%) and surplus (+15%) are general starting points, not individually tailored.
- Doesn't account for specific medical conditions, eating disorders, or clinically prescribed diets.
- If you have a history of disordered eating, please talk to a doctor or registered dietitian before following a structured macro plan.
Questions
Frequently asked questions
How are macros calculated from my calorie target?
Protein is set first, by body weight (1.8 or 2.2 grams per kilogram). Fat is fixed at 25% of total calories to support hormone health. Carbohydrate fills whatever calories remain — it's the most flexible of the three macronutrients for most goals.
Why does protein use a per-kilogram target instead of a percentage?
Research on muscle protein synthesis ties protein needs to body weight, not to total calorie intake. A percentage-based protein target would swing wildly with calorie changes; a per-kilogram target stays stable whether you're cutting or bulking.
Should I choose the standard or higher protein target?
1.8 g/kg covers general health and most recreational training. 2.2 g/kg suits people doing regular resistance training who want to preserve or build muscle, especially while in a calorie deficit.
Do I need to hit these numbers exactly every day?
No. Treat the numbers as a target range — being within roughly 5–10g of each macro on most days is enough for the vast majority of goals. Consistency over weeks matters far more than precision on any single day.
How many grams of protein should I eat per day?
For moderately active adults, 1.2–1.6 g of protein per kg of bodyweight per day is the evidence-based range. Strength athletes and people in a calorie deficit benefit from the higher end (1.6–2.2 g/kg) to preserve lean muscle. This calculator's protein target uses a per-kilogram approach rather than a fixed percentage, which is more accurate for varying body weights.
What should my macros be for weight loss?
For fat loss, prioritise protein (to preserve muscle), moderate carbohydrates (to fuel training and maintain energy), and moderate fat (for hormone function and satiety). A common split for a calorie deficit is 30–35% protein, 35–40% carbs, 25–30% fat — but exact ratios matter less than total calories and adequate protein. The calculator's 'fat loss' goal applies a higher protein ratio for this reason.
Should I count calories or macros?
Counting macros gives you more information than counting calories alone — total calories still drives weight change, but macro balance affects body composition, energy levels, and hunger. For beginners, tracking total calories first is simpler. Once calorie targets feel intuitive, adding protein as a second tracked variable (without worrying about carb/fat split) produces most of the benefit with less effort.
Estimates, not medical advice
FitnessCalculator.info provides general health information for educational purposes only and does not replace advice from a qualified doctor or registered dietitian. If you have a history of disordered eating, please consult a professional before following a calorie or macro target.