Protein Calculator for Muscle Gain

Most lifters building muscle do well on about 1.6 g of protein per kg of bodyweight per day, with 2.2 g/kg as a sensible upper target. Needs rise in a calorie deficit.

Runs in your browser; nothing you type is stored or sent. Estimates only, not medical advice. Updated 2 October 2026.

The formula, written out

For adults who train against resistance, the intake associated with maximal gains in muscle size and strength sits at roughly 1.6 g/kg per day, and the evidence stops showing extra benefit somewhere around 2.2 g/kg. That upper figure is a point where measurable added benefit becomes hard to detect — not a safety ceiling, and not a target you must hit.

When you are eating in a deficit to lose fat, protein needs move up rather than down, because the job changes from adding tissue to defending the tissue you already have. This page uses 1.8–2.4 g/kg for that case.

Two worked examples

A 180 lb lifter building muscle. 180 ÷ 2.20462 = 81.6 kg. Multiply by 1.6 and 2.2 and you get roughly 131–180 g per day. Spread across four eating occasions that is about 33–45 g each.

A 70 kg lifter in a fat-loss phase. Multiply by 1.8 and 2.4 and you get roughly 126–168 g per day. Note this is not far off the first example despite a much lighter bodyweight, which is the point: a deficit raises the requirement.

Protein per day by bodyweight: a reference table

The calculator above runs in your browser, so if you would rather not type anything — or you want to sanity-check the output — here is the same arithmetic worked out in advance. Building uses 1.6–2.2 g/kg. Fat loss uses 1.8–2.4 g/kg, because a calorie deficit raises the requirement rather than lowering it.

Rounded to the nearest gram. Pounds are converted at 2.20462 lb per kilogram. Find the row nearest your bodyweight — the difference between adjacent rows is smaller than the day-to-day variation in how much you actually eat.

How much protein per meal?

This is the question that always follows the daily number, and it matters more than most people expect: a daily total you cannot realistically eat is not a useful target. Divide the daily range across the number of times you actually eat. An 80 kg lifter building muscle lands on 32–44 g at each of four eating occasions.

Spreading intake fairly evenly is mildly better than loading most of it into one meal, because each feeding raises muscle protein synthesis for a few hours and more feedings mean more of those windows. But the effect is small next to simply hitting the daily total. If three larger meals fit your day and four do not, eat three. Total intake and consistent training do the heavy lifting; meal timing is a refinement, not a requirement.

Common questions

Is 1 gram per pound of bodyweight right?

It is a reasonable rule of thumb that happens to sit slightly above the evidence. One gram per pound is about 2.2 g/kg, which is the top of the building range shown here rather than the middle of it. It is not harmful for a healthy adult, but it is not a minimum either — and anyone who tells you results collapse below it is overstating the case. The figure associated with maximal gains is closer to 1.6 g/kg.

Why is this number lower than other protein calculators?

Many calculators are built around that 1 g/lb convention, or are published by companies that also sell protein powder. This page starts from the meta-analysis figures instead and shows the arithmetic, so you can see exactly where the number came from and disagree with it if you want to.

Do I need more protein while cutting?

Yes. It is the one case where the requirement clearly moves up. In a deficit the job changes from adding tissue to defending the tissue you already have, which is why the fat-loss column above is higher than the building column at every single bodyweight.

Can I eat too much protein?

For a healthy adult, intakes well above these ranges have not been shown to cause harm — but they have not been shown to build extra muscle either, and every gram of protein is a gram of something else you did not eat. Past roughly 2.2 g/kg you are trading carbohydrate or fat, both of which fuel training, for no measurable return. If you have kidney disease or any condition affecting protein handling, these ranges do not apply to you.

Should I use my goal weight instead of my current weight?

If you are carrying a lot of body fat, yes — or calculate from an estimated lean mass. Protein requirements track lean tissue, not total mass, so total bodyweight overstates the figure for someone with a high body fat percentage. Understanding what body composition actually measures makes that adjustment easier to judge.

Where this estimate stops being useful

A calculator multiplies two numbers. It does not know you. The range assumes a healthy adult doing regular resistance training, and it uses total bodyweight rather than lean mass, which will overstate the figure for someone carrying a lot of fat — in that case calculating from an estimated lean mass or a goal bodyweight is more sensible.

The range also says nothing about total calories, and protein cannot compensate for eating far too little overall. It says nothing about training quality either. Hitting a protein number while training without progression will not build much of anything, which is why progressive overload matters more than the last ten grams.

If you are pregnant, managing kidney disease, or working with any medical condition that affects how your body handles protein, the figures on this page do not apply to you and this page is not the right source. That is a conversation for a qualified clinician.

Further reading

Phillips SM, Van Loon LJC (2011). Dietary protein for athletes: from requirements to optimum adaptation. Journal of Sports Sciences, 29(S1), S29–S38. PubMed. Basis for the higher range used during energy restriction.

Calculator results are estimates for healthy adults and are not medical or dietary advice. See the full disclaimer.