Enter your weight, goal and age: the tool returns your daily protein range, the dose per meal, and equivalents in everyday foods.
Why a range rather than a number
Protein needs are not a threshold you cross. They are a plateau you reach. Below it, muscle protein synthesis is limited by available substrate. Above it, it is not — and the surplus is simply burned as fuel.
Morton and colleagues pooled 49 studies and nearly 1,900 participants and put that plateau at roughly 1.6 g per kilogram of body weight per day in resistance-trained people, with the upper confidence bound reaching 2.2 g/kg. That is where the range comes from: it covers the uncertainty honestly instead of pretending it away.
What moves the number
Being in a deficit
When calories drop, the body becomes readier to draw on body protein. That is precisely when you need more, not less — the opposite of most people's instinct. Cutting at the top of the range is what protects lean mass while fat comes off.
Age
From around fifty onwards, anabolic resistance sets in: the same dose of protein triggers a smaller muscle response than it did at twenty-five. That is not a dead end, it is a shifted threshold. It simply takes a larger per-meal dose — roughly 30 to 40 g — to get the same answer.
Body composition
Protein feeds lean tissue, not fat tissue. Calculating on total body weight inflates the requirement for someone carrying substantial extra weight. The tool corrects for that.
Does timing across the day matter?
Less than it was once claimed, but it is not nothing. Daily total remains by far the dominant factor. That said, spreading intake across three or four servings of at least 0.4 g/kg each produces a slightly better response than two large meals — a real difference, but a modest one.
Practically: do not force six meals on yourself if three fit your life. The plan you hold for six months beats the optimal plan you drop in three weeks.
Related
- Calorie and macro calculator — where this protein sits in your daily total.
- Volume calculator — the training half of the equation.
- Why you are not gaining muscle — when nutrition is not the problem.
Frequently asked questions
How much protein per day to build muscle?
Between 1.6 and 2.0 g per kilogram of body weight per day covers nearly everyone building muscle. Beyond about 2.2 g/kg, studies stop showing additional benefit in resistance-trained people: the surplus is used as energy.
How much protein per day for a woman?
The recommendation in grams per kilogram is the same as for men — body weight changes, the ratio does not. With matched training, the muscle response to protein intake does not differ meaningfully between sexes.
How much protein after 50?
Needs rise by roughly 0.1 to 0.2 g/kg because of anabolic resistance: muscle responds less to the same dose. It also helps to aim for at least 30 g of protein per meal rather than loading it all onto dinner.
Does high protein damage your kidneys?
In people with healthy kidneys, the available evidence shows no harmful effect from high intakes, including over several years. Where kidney disease already exists, intake should be set by a doctor — that is a clinical matter, not a training one.
Do I need a protein powder?
In most cases, no. Whole food is enough. A protein powder has no special property: it is a convenient food, often cheaper per gram of protein, and useful when hitting your total through meals becomes a chore.