How much protein do I actually need?

Research on active people generally supports 1.6–2.2 g per kilogram of body weight per day, with the higher end useful when in a calorie deficit.

Should fat go below 20% of calories?

Rarely. Dietary fat supports hormone production and the absorption of vitamins A, D, E and K, so most guidance keeps it at or above roughly 20% of intake.

Do I need to hit macros exactly every day?

No. Weekly averages matter far more than daily precision, and being within about 10 g of each target is more than accurate enough.

Macro Calculator

Once you know your calorie target, macros decide what those calories are made of. This calculator converts a daily calorie figure and a chosen split into grams of protein, carbohydrate and fat.

Fill in the fields above and select Calculate to see your result and the full working.

Please note: Health calculators on this site provide general estimates based on population-level formulas. They are not medical advice and cannot account for your individual medical history. Speak to a qualified healthcare professional before making decisions about diet, medication or training.

Formula used

Grams = (calories × percentage) ÷ energy per gram, where protein and carbohydrate supply 4 kcal/g and fat 9 kcal/g

How to use this calculator

Work out your calorie target first — the calorie calculator does this for you.
Enter the target and choose a split, or select custom and enter your own percentages.
Custom percentages must add up to 100%.
Use the gram targets in a food diary; hitting protein consistently matters more than hitting all three exactly.

Example calculation

A 2,200 kcal target on a balanced 30/40/30 split:

Protein = 2,200 × 0.30 ÷ 4 = 165 g

Carbs = 2,200 × 0.40 ÷ 4 = 220 g

Fat = 2,200 × 0.30 ÷ 9 = 73 g.

What does this result mean?

Total calories drive weight change; macros influence body composition, satiety and training performance. Higher protein helps preserve muscle in a deficit and keeps you fuller. Endurance athletes generally need more carbohydrate; some people simply prefer more fat. Any split that you can follow consistently and that meets protein needs will work.

Frequently asked questions

How much protein do I actually need?: Research on active people generally supports 1.6–2.2 g per kilogram of body weight per day, with the higher end useful when in a calorie deficit.
Should fat go below 20% of calories?: Rarely. Dietary fat supports hormone production and the absorption of vitamins A, D, E and K, so most guidance keeps it at or above roughly 20% of intake.
Do I need to hit macros exactly every day?: No. Weekly averages matter far more than daily precision, and being within about 10 g of each target is more than accurate enough.

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