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Macro Calculator

Enter your details, activity level and goal to see a daily calorie target split into protein, carbohydrate and fat, in grams.

Your details

Sex
years
This calculator is for adults aged 18 and over.
Before we calculate — do any of these apply?
If you tick any of these, the calculator will not set macro targets and will point you to tailored advice instead.
Daily calorie target
2,740 kcal/day
Protein
137 g
Carbohydrate
343 g
Fat
91 g

A balanced split at your estimated maintenance calories.

Balanced split: 20% protein · 50% carbohydrate · 30% fat

Estimate only. Macro targets are general estimates, not a medical diet plan. Protein, carbohydrate and fat needs vary with health, training, food preferences and other factors. If you are pregnant, breastfeeding, under 18, managing a health condition, following a prescribed diet, taking medication that may affect weight, appetite or blood sugar, or have a history of disordered eating, seek personalised advice from a qualified health professional.

How to use this calculator

  1. Pick your sex, enter your age, height and weight.
  2. Choose the activity level that best reflects your typical week.
  3. Choose your goal — lose, maintain, or gain weight.
  4. Answer the short “before we calculate” safety questions. If any apply, the calculator points you to tailored advice instead of setting macro targets.
  5. Read your daily calorie target and your protein, carbohydrate and fat targets in grams.

Nothing is submitted anywhere. The calculation runs in the page as you type, and the link in your address bar carries your figures, so it can be shared or bookmarked.

How are macros calculated?

Grams = (Calorie target × Macro % ÷ 100) ÷ kcal per gram
  • Protein and carbohydrate: 4 kcal per gram. Fat: 9 kcal per gram.
  • Lose weight — 30% protein / 45% carbohydrate / 25% fat, at maintenance − 300 kcal/day.
  • Maintain weight — 20% protein / 50% carbohydrate / 30% fat, at maintenance calories.
  • Gain weight — 20% protein / 55% carbohydrate / 25% fat, at maintenance + 300 kcal/day.

Worked example. A 30-year-old, 178 cm, 80 kg man with moderate activity and a "maintain weight" goal has estimated maintenance calories of 2,740 kcal/day. At the balanced 20/50/30 split, that is 137 g protein (2,740 × 0.20 ÷ 4), 343 g carbohydrate (2,740 × 0.50 ÷ 4), and 91 g fat (2,740 × 0.30 ÷ 9).

Related tools

Want just the calorie number, with more control over the pace? Use the weight loss calorie calculator or the weight gain calorie calculator. For a protein target based on your weight and training goal alone, see the protein intake calculator.

Frequently asked questions

What is a macro calculator?

It turns a daily calorie target into grams of protein, carbohydrate and fat — the three "macros" — based on your details, activity level and goal (lose, maintain or gain weight).

How are the calorie and macro targets calculated?

BMR comes from the Mifflin–St Jeor equation, scaled by your activity level to estimate maintenance calories, then adjusted by a mild deficit or surplus for your goal. That calorie target is split into protein, carbohydrate and fat by percentage, then converted to grams using 4 kcal per gram of protein and carbohydrate, and 9 kcal per gram of fat.

Why does the macro split change with my goal?

A weight-loss goal uses a higher protein share to help protect lean mass during a deficit. A weight-gain goal uses extra carbohydrate to help fuel training. All three splits sit inside the Acceptable Macronutrient Distribution Range (AMDR) — the range of protein, carbohydrate and fat intake published in the Institute of Medicine’s Dietary Reference Intakes.

Can I use a different macro split than the one shown?

Yes — these are sensible starting points, not the only valid split. If you have a specific target (for example, a higher-protein diet for strength training), calculate the calories that split works out to and adjust from there; the protein intake calculator gives a bodyweight-based protein target you can start from instead.

What is the difference between this and the calorie deficit or weight gain calorie calculator?

Those two give a single daily calorie number with more control over the pace (several preset deficits or surpluses, plus a custom option). This calculator gives a smaller set of goals but breaks the result down into protein, carbohydrate and fat grams as well as calories.

Why won’t the calculator show my macro targets?

It applies the same safety limits as the weight loss and weight gain calorie calculators, so a restricted plan cannot be reached by asking for it as macros. It shows tailored-advice copy instead of a number when the age entered is under 18, when a pregnancy, health condition, prescribed diet, relevant medication or eating-disorder history is disclosed, or when a weight-loss goal would put the daily calorie target below about 1,500 kcal for a male entry, below about 1,200 kcal for a female entry, or below your own estimated resting metabolic rate. In those cases, speak with a GP or registered dietitian.

Is this a meal plan or medical advice?

No. The calorie and macro figures are general estimates for information only, not a medical diet plan, diagnosis or treatment recommendation, and there is no NHS or dietitian endorsement of the split. Protein, carbohydrate and fat needs vary with health, training, food preferences and other factors.