Calculator Nutrition

Protein calculator

Protein needs scale with body weight and what you're asking your body to do. Enter your weight and goal for a sensible daily range in grams — then see it as macros with the macro calculator.

By the numbers Context

How much protein you actually need

Protein is the building block your body uses to repair and build muscle, and it is the most filling of the three macronutrients. The official RDA is 0.8 grams per kilogram of bodyweight, but that figure is set to prevent deficiency in a sedentary adult — not to optimise strength, recovery, or fullness. People who train, who are dieting, or who are older generally do better with more.

For building or preserving muscle, a large body of research supports roughly 1.6 to 2.2 grams per kilogram — about 0.7 to 1 gram per pound of bodyweight. Older adults benefit from the higher end to counter age-related muscle loss. Spreading it across meals, at around 20 to 40 grams each, uses it more effectively than one large serving. This calculator turns your weight and goal into a daily target.

0.8 g/kg

the RDA minimum for a sedentary adult

NIH

1.6–2.2 g/kg

common range for building or retaining muscle

Research

20–40 g

protein per meal that best supports muscle repair

Research

Sources: U.S. National Institutes of Health (RDA); protein and resistance-training meta-analyses.

Frequently asked questions

How much protein do I need a day?

It depends on your weight and activity. The minimum RDA is 0.8 g per kg, but active people aiming to build or keep muscle usually target 1.6–2.2 g per kg (about 0.7–1 g per pound). This calculator gives a personalised range.

Is 100 g of protein a day a lot?

For a smaller or sedentary person it may be plenty or even generous; for a larger or very active person it may be on the low side. Whether 100 g is “a lot” depends entirely on your bodyweight and goals.

Is 30 g of protein a day too little?

For almost any adult, 30 g a day is well below what is recommended — it is closer to a single good serving than a full day’s intake. Most adults need substantially more.

How do I calculate my protein needs?

Multiply your bodyweight by a factor for your goal — roughly 0.8 g/kg to maintain basic health, up to about 2.2 g/kg to build muscle. This calculator does the maths from your weight and goal.

Do I need more protein to build muscle?

Yes. Building muscle requires both resistance training and enough protein — generally 1.6–2.2 g per kg of bodyweight — to supply the raw material for repair and growth.

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This page is educational and is not medical advice. Calculators use standard formulas and give estimates — discuss anything that concerns you with a qualified professional.