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GLP-1 protein calculator

This calculator gives you a daily protein target, protein per meal, a fibre range and a fluid target for weight loss on semaglutide or tirzepatide. Enter your sex, height, weight and how your appetite is right now.

How it's calculated

First it estimates your ideal body weight with the Devine formula (50 kg for men or 45.5 kg for women, plus 0.9055 kg for every cm above 152.4 cm). If your weight is more than 20% above that, it uses an adjusted body weight: ideal weight plus 40% of the difference. This is the method clinicians use so protein targets stay realistic at higher body weights.

Protein is then 1.5 g per kg of that reference weight, rounded to 5 g and kept between 80 g and 180 g a day. That sits within the 1.4–2.0 g/kg range the International Society of Sports Nutrition (ISSN) position stand describes for people who exercise, and at the practical end for someone losing weight with a reduced appetite.

The total is split by appetite: 3 meals if your appetite is normal, 4 if it varies and 5 if it is low. Fibre is set at 25–30 g a day, reached gradually. Fluids are about 33 ml per kg of body weight, between 2 and 3.5 litres.

The result is a starting point, not a prescription. If you have kidney disease, ask your doctor or dietitian for your protein target. To get the full 12-week strength plan built around these numbers, use the plan builder.

Frequently asked questions

Why does the calculator use adjusted body weight?

Using full body weight at a high BMI can produce protein targets well over 200 g a day, which are hard to eat and not needed, since fat tissue needs little protein. Adjusted body weight is a standard clinical compromise that keeps the target proportionate to your lean mass.

Is 1.5 g/kg of protein safe?

For healthy adults with normal kidney function, intakes in this range are considered safe and are commonly recommended during weight loss. If you have kidney disease or have been told to limit protein, follow your doctor's or dietitian's advice instead of this number.

Does the target change between Ozempic and Mounjaro?

No. The protein, fibre and fluid targets depend on your body and appetite, not on which GLP-1 medicine you take. Your appetite setting does change how many meals the total is split into.

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General fitness information, not medical advice. Check with a doctor if you have a medical condition, are pregnant or have an injury.