How this calculator works
Three inputs, one formula. The calculator multiplies your goal body weight in kilograms by a figure between 1.6 and 2.2 grams, and divides the result across the number of meals you actually eat.
That range is the one clinical nutrition research supports for adults in a caloric deficit who are trying to hold onto lean mass. Your resistance-training frequency decides where inside it you land: not training yet puts you at 1.6 g/kg, training once or twice a week at 1.9, and training three or more times a week at 2.2. More loading stimulus means more of the protein you eat is actually put to work.
Why goal weight, not current weight
This is the part most protein calculators get wrong, and it is the difference between a target you can eat and one you will abandon in a week.
Protein requirements track lean tissue, not total mass. Body fat does not need feeding. If you weigh 260 lb and you are working toward 180, calculating from 260 produces roughly 260 g of protein a day — a number almost nobody can eat on a suppressed appetite, and one you do not actually need. Calculating from 180 gives you about 180 g, which is demanding but achievable.
If you do not have a specific goal weight in mind, leave the field blank. The calculator falls back to your current weight, which at the low end of the range is a reasonable stand-in.
Why the number is double what you have heard
The U.S. RDA for protein — 0.8 g/kg — is the figure most people have absorbed as correct. It is not wrong exactly. It is answering a different question.
That number was calculated in 1980 to prevent deficiency in sedentary adults eating at energy balance. Not losing weight. Not over 40. Not on a medication that suppresses appetite by 20 to 40%. If you are on a GLP-1 and losing weight, you are very likely several of those things at once — and at real risk of losing lean tissue alongside fat. The full reasoning, with the research behind it, is in how much protein you actually need on Ozempic.
The per-meal number is the one to watch
Most protein advice stops at the daily total. That is the wrong unit of measurement.
Muscle building runs on a per-meal trigger. Each meal needs roughly 25 to 40 grams of quality protein to clear the leucine threshold that switches on muscle protein synthesis. Below that threshold the switch does not flip, no matter how much protein arrives later in the day. Three meals of 35 g will do more for your muscle than six snacks of 17 g, even though the daily totals are nearly identical.
This is why the calculator asks how many meals you eat. If it tells you your per-meal number has fallen below 25 g, the fix is to eat fewer, larger meals — not to spread the same protein thinner.
How to hit the number when you have no appetite
The cruel irony of a GLP-1 is that the drug helping you lose weight is actively working against your ability to hit this target. Delayed gastric emptying means you feel full faster. Blunted food reward makes dense savory protein less appealing. Dose-escalation nausea cuts intake further, right when your needs are highest.
- Front-load the day. Get 30–40 g within an hour of waking, before appetite suppression peaks.
- Protein first, every meal. Put it on the plate first and eat it first. By the time fullness arrives mid-meal, the highest-value food is already in you.
- Schedule, don’t sense. Hunger stops being a reliable clock on a GLP-1. Use an actual one.
- Lean on liquid protein on hard days. A shake goes down when a chicken breast will not. That is not cheating — it is the workaround the physiology demands.
Protein without a loading stimulus does far less than the two together. If you are not training yet, start with the best exercises to preserve muscle on GLP-1 drugs. If you are not sure whether muscle loss is already happening to you, the ten-minute self-check in Are You Losing Muscle On Ozempic? will tell you whether this is urgent or preventive. And once protein and training are in place, creatine is the one supplement with enough evidence to add next.
Frequently asked questions
How much protein should I eat on Ozempic?
For most adults on a GLP-1 in active weight loss, 1.6 to 2.2 grams per kilogram of goal body weight per day — roughly double the standard RDA of 0.8 g/kg. Where you land inside that range depends mostly on how much resistance training you do. Split the total across 3 to 4 meals of at least 25 to 30 g each rather than trying to hit it in one or two large meals.
Should the calculator use my current weight or my goal weight?
Goal weight, if you have one. Protein requirements track lean tissue rather than total mass, and body fat does not need feeding. Someone at 260 lb working toward 180 who calculates from 260 gets a number most people cannot eat on a suppressed appetite and do not actually need. If you have no specific goal weight, using current weight at the low end of the range is a reasonable stand-in.
Why is the standard protein RDA wrong for people on GLP-1 medications?
The U.S. RDA of 0.8 g/kg was calculated in 1980 to prevent deficiency in sedentary adults eating at energy balance. It was never designed for someone in a significant caloric deficit, often over 40, on a medication that suppresses appetite by 20 to 40%, trying to preserve muscle. Those conditions raise protein needs substantially.
Does the per-meal number really matter more than the daily total?
It matters more than most people expect. Muscle protein synthesis runs on a per-meal trigger — each meal needs roughly 25 to 40 g of quality protein to clear the leucine threshold that switches it on. Three 35 g meals do more for muscle than six 17 g snacks, even though the daily total is nearly identical.
What if I can't eat that much protein because I have no appetite?
Work down a hierarchy on hard days: fluids and electrolytes first if hydration is slipping, then protein at whatever meal you tolerate best, then soft or liquid protein like a shake or Greek yogurt when solid food will not go down. Getting to step two on a bad day still protects meaningful muscle. Consistent-enough beats perfect.
Is this calculator safe for everyone?
No calculator is. These are educational planning ranges for healthy adults. Kidney disease, liver disease, pregnancy, and a history of eating disorders all require a personalized target set with your clinician or a registered dietitian. Bring the number here to that conversation rather than using it instead of one.