Macro Calculator (Protein, Carbs and Fat)

This macro calculator splits a daily calorie target into grams of protein, carbohydrate and fat: a 2,000 kcal day at 25% protein, 50% carbs and 25% fat is 125 g protein, 250 g carbs and 56 g fat. Protein and carbohydrate provide 4 kcal per gram and fat 9 kcal per gram, which is how the grams are worked out.

  • Protein4 kcal per gram
  • Carbohydrate4 kcal per gram
  • Fat9 kcal per gram

Updated November 2026 · Uses UK food label energy factors

This calculator is for general information and is not medical or dietary advice. If you have a medical condition, are pregnant, have diabetes or kidney disease, or have had an eating disorder, speak to your GP or a registered dietitian before changing your diet.

Calculate your macros

Use our BMR calculator if you do not know it.
Used to show protein per kg.
Custom split only. The three must add up to 100.

Your result

Fill in the details, then press Calculate to see your result with the working shown.

How to calculate macros

Start with a daily calorie target, then choose what share of those calories comes from each macronutrient. Divide the protein and carbohydrate calories by 4 and the fat calories by 9 to get grams. For 2,000 kcal at 25% protein: 2,000 × 0.25 = 500 kcal, and 500 ÷ 4 = 125 g of protein.

Alcohol also contains energy (7 kcal per gram), so drinks count towards your calorie total even though they are not a macro you need.

Macro splits for weight loss, maintenance and muscle gain

GoalProteinCarbsFatAt 2,000 kcal
Balanced / maintenance25%50%25%125 g P, 250 g C, 56 g F
Fat loss (higher protein)35%35%30%175 g P, 175 g C, 67 g F
Muscle gain30%45%25%150 g P, 225 g C, 56 g F
Lower carb30%20%50%150 g P, 100 g C, 111 g F

These are common starting points rather than rules. For fat loss, the calorie deficit matters most; a higher protein share helps you feel full and keep muscle. For muscle gain, a small calorie surplus plus resistance training matters more than the exact split.

UK reference intakes on food labels

NutrientReference intake for an adult (per day)
Energy2,000 kcal (8,400 kJ)
Fat70 g
of which saturates20 g
Carbohydrate260 g
of which sugars90 g
Protein50 g
Salt6 g

Reference intakes are the figures behind the “% RI” on UK food labels. They describe an average adult diet, not a target for everyone. Adults should also keep free sugars to no more than 30 g a day.

How much protein do you need?

The UK reference nutrient intake for adults is 0.75 g of protein per kg of body weight a day, about 52 g for a 70 kg adult. Most UK adults already eat more than this. People who are very active or trying to keep muscle while losing weight often aim higher, and the calculator shows your protein per kg so you can compare.

Frequently asked questions

How many grams of protein, carbs and fat should I eat on 2,000 calories?

On a balanced 25/50/25 split, 2,000 kcal is about 125 g protein, 250 g carbohydrate and 56 g fat.

How do you convert calories to grams of protein?

Divide by 4. For example, 600 kcal from protein is 150 g. Carbohydrate is also 4 kcal per gram, while fat is 9 kcal per gram.

What is the best macro split for weight loss?

A common starting point is about 35% protein, 35% carbs and 30% fat within a calorie deficit. The deficit drives weight loss; the higher protein helps with fullness.

How much protein should I eat a day in the UK?

The adult reference nutrient intake is 0.75 g per kg of body weight, around 52 g a day for someone weighing 70 kg.

What are the reference intakes on UK food labels?

For an average adult: 2,000 kcal, 70 g fat, 20 g saturates, 260 g carbohydrate, 90 g sugars, 50 g protein and 6 g salt a day.

Sources and method

We use official UK guidance and recognised formulas, and test each calculator against worked examples. Results are estimates to help you plan, not professional advice. See how we work.