A daily protein target in grams, based on your weight, your training and what you are trying to do — with the number pushed higher if you are losing weight on Mounjaro or Wegovy.
Protein a day
Pick your goal, add your details, then press Calculate my protein.
Chicken breast
100 g cooked
31 g
Salmon fillet
100 g cooked
25 g
Greek yoghurt
170 g pot
17 g
Eggs
2 large
13 g
Firm tofu
100 g
17 g
Tinned chickpeas
half a tin, drained
12 g
In a calorie deficit your body covers the shortfall from its own tissue, and some of that is muscle unless you give it a reason not to. Protein is that reason. It is also the most filling of the three macronutrients, which makes the deficit easier to hold in the first place.
Mounjaro and Wegovy work by reducing appetite, so the deficit tends to be larger and the loss faster. Faster loss costs proportionally more lean mass, and a smaller appetite makes a protein target harder to hit by accident. Both point the same way: protein first, at every meal.
Protein supplies the material; training supplies the signal to keep it. Two or three sessions a week, working the major muscle groups, does far more to protect lean mass than protein alone. Neither substitutes for the other.
Most people use roughly 25 to 40 g in a sitting for muscle repair. Three or four meals inside that window beats one large evening hit, which is also the pattern that suits a reduced appetite best.
The other half is the size of the deficit it sits inside. Work out the calories that take you to your goal weight, then use this target to decide what those calories are made of.
This calculator gives general information based on population guidance, not medical or dietetic advice. It is written for healthy adults. If you have reduced kidney function, kidney or liver disease, are pregnant or breastfeeding, or are being treated for a condition that affects your diet, your protein intake should be set by your doctor or dietitian and their advice takes precedence over anything shown here.
Built by the CoolDose teamLast updated
The UK reference intake. 0.75 g of protein per kilogram of body weight a day is the amount that prevents deficiency, not the amount that protects muscle while you lose weight or train. Every range here starts above it. nhs.uk
Higher intakes while losing weight. In a calorie deficit the body draws on its own tissue, muscle included. Mainstream sports-nutrition guidance puts the range that protects lean mass at roughly 1.2 to 2.0 g per kilogram. This calculator works between 0.8 and 2.4 g per kilogram, because it also adjusts for how active you are — a quiet week at maintenance sits below that band and hard training sits above it — and it holds the floor at 1.2 whenever you are losing weight.
Adjusted body weight above a BMI of 30. Grams per kilogram assumes the kilograms are metabolically active. Fat tissue needs very little protein, so above that point the target is worked out on the top of the healthy weight range for your height plus 40% of the excess — the usual clinical adjustment — and the figure used is shown to you.
Protein and GLP-1 medication. Weight comes off faster on a GLP-1 and a larger share of it can be lean mass, while a reduced appetite makes a protein target harder to hit by accident. That is why ticking the GLP-1 box aims you at the upper half of the range rather than a separate number invented for it.
The UK reference intake is 0.75 g per kilogram of body weight a day, which is the amount that stops you becoming deficient. It is not the amount that keeps muscle on you while you lose weight or train. Most people doing either land between 1.2 and 2.0 g per kilogram. This calculator spans 0.8 to 2.4, because it also adjusts for how active you are: a quiet week at maintenance sits below that band, and training hard to build muscle sits above it. While you are losing weight it never goes below 1.2, whatever your activity level.
In a calorie deficit your body will take some of what it needs from its own tissue, and that includes muscle. Eating more protein, and using it, shifts the balance so more of the loss comes from fat. Muscle is also what keeps your metabolic rate up, so protecting it protects the deficit.
It matters a lot. Weight comes off faster on a GLP-1, and faster loss costs proportionally more lean mass. Appetite is also suppressed, so hitting a protein target takes deliberate planning rather than happening by accident. Tick the GLP-1 box and the calculator aims you at the upper half of the range.
Grams per kilogram assumes the kilograms are metabolically active. Fat tissue needs very little protein, so at a BMI over 30 the plain calculation over-states the target. Above that point we calculate on the top of the healthy weight range for your height plus 40% of the excess — the usual clinical adjustment — and tell you the figure we used.
It helps. Roughly 25 to 40 g in a sitting is about as much as most people use for muscle repair at once, so three or four meals in that window works better than one large hit at dinner. The result shows both splits.
For healthy adults there is little evidence of harm at the intakes shown here, and no benefit above about 2.4 g per kilogram, which is where this calculator stops. If you have reduced kidney function, or any kidney disease, protein intake needs to be set by your doctor rather than a calculator.
No. Powder is convenient, not necessary — it is simply a fast 20 to 25 g. If food gets you there, food is fine. On a GLP-1, when appetite is low and volume is a problem, a shake can be the easiest way to close a gap.
No. This is general information based on population guidance. If you are pregnant or breastfeeding, have kidney or liver disease, or are being treated for anything that affects your diet, follow the advice you have been given rather than this calculator.