Protein Requirement Calculator

Before anything else

This page has options on it for fever, infection, protein depletion and burns. Those are not lifestyle settings. They are clinical states, and in a clinical state protein is set by someone who can see the whole picture: kidney function, what is being treated, what else is going on, and how the person is actually responding. A burns target in particular is calculated and revised by a dietitian against the size of the injury.

So read what follows as background on where the numbers come from, not as a plan. If you or someone you are caring for is ill, injured or recovering, the number that matters comes from your clinical team, and it may not look like the number here.

This one is not from the gym

Look at the dropdown on this tool and you will notice it does not belong with the others. There is no activity level and no goal. There is no place to say you want to lose a few kilos before a wedding. What it asks is your weight and your condition, and the conditions are fever, fracture, infection, protein depletion and extensive burns.

This is a clinical table. The figures behind it are the ones used in hospital nutrition, where working out how much protein a patient needs is not a lifestyle question but part of whether they heal. Intensive training is on the list almost as an afterthought, the one entry that belongs to the world of the other calculators.

Enter a weight of 70 kg and here is the whole tool laid out:

Top row to bottom row, the requirement roughly triples. Same person, same 70 kg. The rest of this page is about why.

What a severe burn does to a body

The bottom row is the one worth understanding, because what happens to a badly burned person is one of the most extreme things the human metabolism does, and almost nobody outside a burns unit knows about it.

You would reasonably assume a burn is a skin problem. It is not. A severe burn triggers a whole-body response that turns the metabolism up and leaves it there. Adrenaline, cortisol and glucagon flood the system, and the body flips into a state where it is tearing itself down for parts. Muscle is broken down for amino acids, blood sugar climbs, and the ordinary business of building things stops.

The scale of it is genuinely hard to believe. Metabolic rates in burn patients can exceed twice normal. Not by ten percent. Double. And this is not a bad week that passes: patients can remain in that hypermetabolic, hypercatabolic state for months after the injury, losing something in the region of a fifth to a quarter of their body weight while it runs.

Protein is being attacked from two directions at once. The body is dismantling muscle internally for fuel, and separately the wound itself is leaking protein out through the exudate, while the new tissue being built underneath is consuming still more. Every one of those routes is a drain, and none of them switches off because you would prefer it to.

So the figure climbs to as much as 3 grams per kilogram, and it is not enthusiasm. It is arithmetic. Fail to meet it and the consequences are not disappointing gym results: wound healing slows, infection risk rises, and organs start to struggle. Hospital guidance settles at a minimum of around 1.5 to 2 g/kg for burns, with the higher figures reserved for the most severe cases, and it is delivered under supervision with the patient's nitrogen balance actually measured rather than estimated.

Why a fever and a broken bone sit in the same row

It looks like an odd grouping. A temperature, a fractured wrist and an infection have very little in common from the outside.

From the inside they are the same event. Each one puts the body into the same catabolic gear as the burn, just with the dial turned down. Your metabolic rate rises, muscle protein starts being broken down to supply amino acids for the immune system and for repair, and demand outruns whatever you were eating last week. A fever alone lifts your energy burn simply by running you hotter. A fracture commits you to building bone and tissue for weeks. An infection funds an immune response that is expensive in exactly the currency this tool measures.

Hence 1.5 to 2 g/kg, roughly double the healthy figure. And hence the cruel irony that everybody who has ever been ill will recognise: the moment your body needs the most protein it has ever needed is the moment you least feel like eating anything at all.

Protein depleted, and what that actually describes

This is the one option on the list that is not an event but a state. Protein depletion means the body has already been running a deficit long enough to have eaten into itself: muscle wasted, immune function down, healing slowed. It is what you find after a long illness, after prolonged undernutrition, or after weeks of the catabolic state described above going unfed.

The figure is the same 1.5 to 2 g/kg, and the reasoning is different. The others are covering an ongoing drain. This one is paying back a debt, supplying the material to rebuild what has already gone.

It is worth saying that protein depletion is a clinical assessment rather than a self-diagnosis. It is not the same as feeling run down, and it is not what you have after a stressful fortnight.

The healthy baseline, and why it is so much lower

Which brings us back to the top row and the familiar 0.8 to 1.0 g/kg.

That figure is the Recommended Dietary Allowance, and it deserves the same caveat here that it gets everywhere else on this site: it is a floor, not a target. It is the intake calculated to stop nearly every healthy adult becoming deficient, and it answers the question of how little you can get away with rather than what would serve you well. Our Protein Intake Calculator explains how that number is constructed and why it is so widely misread.

Notice too how conservative the intensive training row is by comparison, at 0.8 to 1.5 g/kg. That top end sits at the bottom of what sports nutrition actually recommends. The joint position of the Academy of Nutrition and Dietetics, Dietitians of Canada and the American College of Sports Medicine puts active people at 1.2 to 2.0 g/kg. So if you came to this tool as a healthy person who lifts, this is not the right table for you, and our Protein Intake Calculator is built for that question.

The genuinely striking thing about this table is the comparison it invites. A serious burn demands more protein per kilogram than any athlete on earth. Nobody in a gym is operating at 3 g/kg out of necessity. A person in a burns unit is.

If you are actually in one of these situations

We should be plain about this, because of what is in that dropdown.

If you have extensive burns, or an infection serious enough to change your metabolism, or you have been assessed as protein depleted, you need a clinician and not a web page. Not because the numbers here are wrong, but because in those situations the number is the easy part. What matters is whether you can absorb it, whether it goes in by mouth or another route, how it is phased as you recover, and what your bloods are doing while it happens. Those are decisions made with measurements, by people who can see you.

What this tool is genuinely good for is understanding. If you are recovering from a fracture at home and wondering why you feel so hungry and so wasted, or you are looking after someone who is unwell and cannot understand why they seem to be melting away, this table explains it. That is worth knowing. It just is not a treatment plan.

Questions people ask

Why does being ill raise protein needs so much?

Because illness and injury switch the body into a catabolic state, breaking down muscle to supply the immune system and tissue repair. The demand is real and it runs whether you feed it or not. If you do not supply the protein, your body takes it from you.

What if I cannot eat that much while I am ill?

That is extremely common and it is one of the main reasons illness costs people muscle. Small, frequent, protein-dense food tends to work better than big meals. If you genuinely cannot manage it and the illness is dragging on, that is worth raising with your doctor, because it is a solvable problem and one they take seriously.

Which option should I pick if more than one applies?

The tool takes one condition at a time and does not stack them. In reality they compound, which is one of several reasons a real case needs a clinician rather than a dropdown.

I am healthy. Which row is mine?

The top one, and treat it as a minimum rather than a goal. If you train, use our Protein Intake Calculator instead, because the training row here is more conservative than current sports nutrition guidance.

References

Where the figures come from. The hypermetabolic response to severe burns, including metabolic rates exceeding twice normal and the prolonged catabolic state, is described by Rousseau and colleagues and in a review of nutrition and metabolism in burn patients. The protein recommendation of at least 1.5 to 2 g/kg per day for burns, and the losses through wound exudate, are from a recent review of nutrition considerations for burn patients. The 0.8 g/kg Recommended Dietary Allowance is from the Institute of Medicine's Dietary Reference Intakes, and the 1.2 to 2.0 g/kg range for active people is the joint position of the Academy of Nutrition and Dietetics, Dietitians of Canada and the American College of Sports Medicine.

1. Rojas Y, Finnerty CC, Radhakrishnan RS, Herndon DN. Nutrition and metabolism in burn patients. Burns & Trauma. https://pmc.ncbi.nlm.nih.gov/articles/PMC5393025/
2. Nutrition considerations for burn patients: optimizing recovery and healing. https://pmc.ncbi.nlm.nih.gov/articles/PMC11571818/
3. Protein nutritional support in critically ill patients: pathophysiological basis, clinical evidence, and areas of uncertainty. Frontiers in Medicine. https://pmc.ncbi.nlm.nih.gov/articles/PMC13106382/
4. National Academies of Sciences, Engineering, and Medicine. Dietary Reference Intakes for Energy. Washington DC: The National Academies Press. https://www.ncbi.nlm.nih.gov/books/NBK591020/
5. Thomas DT, Erdman KA, Burke LM. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: nutrition and athletic performance. Journal of the Academy of Nutrition and Dietetics. 2016;116(3):501-528.