Protein intake calculator

Where these numbers come from

This calculator does not invent a target. It takes reference ranges that have already been published by expert bodies and converts them from grams per kilogram of body weight into grams per day for the weight you entered — which is arithmetic, not advice. The three references are listed above the tool with their publishers and years so you can go and read them.

The anchor most people have heard of is the Recommended Dietary Allowance of 0.8 g of protein per kg of body weight per day, set for healthy adults in the Institute of Medicine's 2005 Dietary Reference Intakes. It is worth understanding what an RDA actually is: it is the intake estimated to be sufficient to meet the requirement of nearly all healthy people in a group. It is a floor built to prevent deficiency across a population — not a performance target, and not a recommendation that you should aim for exactly that figure.

The same report gives an Acceptable Macronutrient Distribution Range of 10–35% of daily energy from protein, which is a much wider window and a reminder that there is no single correct number. The higher band the calculator shows, roughly 1.2–1.6 g per kg per day, is the region discussed in published reviews of protein intake during weight loss; a separate consensus paper on older adults lands at 1.0–1.2 g per kg. Ranges that overlap and disagree at the edges are what the evidence honestly looks like.

Why protein comes up so often during weight loss

Two reasons, and they compound. The first is that losing weight means losing some lean tissue alongside fat unless something is done about it, and protein intake together with resistance training is the lever most often discussed for limiting that. The second is specific to appetite: when appetite drops sharply, total food intake falls, and protein tends to fall with it — not because anyone decided to eat less of it, but because eating less of everything eats less of everything.

That is why the per-meal split matters more than the daily figure for a lot of people. A daily number you cannot physically get through in three sittings is not a plan. Seeing the same target divided across four or five smaller occasions is often the difference between a figure that feels impossible and one that is merely a bit of organising. Our guide to protein while appetite is reduced goes into the practical side, and high-protein foods covers what to actually put on the plate.

Splitting the daily figure across meals

The calculator divides whichever range you are looking at by the number of eating occasions you choose, and shows the per-occasion figure next to the daily one. That is deliberately the second number on the screen rather than a footnote, because the daily total is the figure people quote and the per-meal figure is the one that decides whether the daily total is achievable at all.

An even split is a starting point, not a rule — nobody eats identically at every sitting, and there is no published requirement that says you must. What an even split is good for is a reality check. If dividing your figure across three meals produces a per-meal number you would struggle to finish, the honest conclusion is usually that you need more eating occasions rather than larger ones, and that is a much easier thing to change than your appetite.

Grams of protein, not grams of food

This trips up almost everyone the first time. The figures here are grams of protein, not grams of a food that happens to contain protein. A 100 g chicken breast is not 100 g of protein — it is roughly 30 g. A large egg is around 6 g. A 170 g container of Greek yogurt is around 17 g. So a target that looks impossible in food terms is usually a target you have mentally converted at the wrong exchange rate, and the fix is to read a label rather than to abandon the number.