Should I dose per kg of body weight or per kg of lean mass?

Per kg of lean mass is the cleaner anchor for lean and trained people. Per kg of body weight is simpler and works in the average body-fat range. The two converge as you lose fat: at 15 percent body fat, 1.8 g/kg of body weight equals about 2.1 g/kg of lean mass. This calculator uses body weight for maintain and build, and lean mass for recomposition and cut.

Is more than 2.2 g/kg useless?

Not useless, but probably not for muscle. In Morton 2018, the top of the confidence interval for the plateau was 2.2 g/kg, and the authors suggest about 2.2 g/kg for people who want the most muscle from training. Protein above that still costs energy to digest (20 to 30 percent of its calories, Westerterp 2004). In a deficit, Helms 2014 recommends 2.3 to 3.1 g per kg of lean mass for lean, trained people.

Does timing matter, or only the daily total?

The daily total matters most. Helms 2014 found that nutrient timing and meal frequency appear to have little effect on fat loss or lean-mass retention. For muscle gain outside a deficit, Schoenfeld & Aragon 2018 suggest about 0.4 g per kg of body weight per meal across at least four meals, which adds up to 1.6 g/kg a day.

Is high protein safe for kidneys?

In healthy adults, the evidence says yes. Devries et al. (J Nutr 2018, meta-analysis of 28 trials with 1,358 participants) found that kidney function, measured as the change in glomerular filtration rate, did not differ between higher- and lower-protein diets. The warning that circulates online applies to people with kidney disease, who should follow their doctor's advice.

What counts as a complete protein source?

Any source with all nine essential amino acids in adequate proportions. Animal products and soy are complete on their own. Plant sources combine into completeness across a normal day, which is why the original complementing-proteins advice was retracted by Frances Moore Lappe herself. Hit the daily total and quality usually takes care of itself.

Protein Intake Calculator: Grams per Day (g/kg)

Why protein matters for body recomposition

Your body has no dedicated protein store the way it stores fat and glycogen, so protein has to come from food. It is broken down into amino acids that build and repair muscle, organs and immune tissue. In a calorie deficit, eating enough of it helps limit lean-mass loss.

The calculator above takes weight, body fat, training experience and goal and picks a starting dose from the research. With body fat entered, recomposition and cut targets scale to lean body mass instead of total weight, and maintenance and muscle-gain targets never exceed the recomposition target.

The result shows your daily target, what it costs to digest, how it splits across meals, where it sits on the Morton 2018 muscle-gain curve, and what it looks like in plain food.

The protein dose across recomposition phases

The calculator uses one setting per goal. Body-weight (BW) and lean-mass (LBM) settings are not directly comparable: at 20 percent body fat, 2.2 g/kg LBM equals about 1.76 g/kg BW. Maintenance and muscle-gain settings are capped at the recomposition setting, so at higher body fat they follow lean mass.

Maintain

1.6 g/kg BW

Inside the ISSN 2017 range of 1.4 to 2.0 g/kg BW for most people who exercise.

Build muscle

1.8 g/kg BW

Above the 1.62 g/kg BW break point in Morton 2018, inside its 95% CI.

Recomposition

2.2 g/kg LBM

The calculator’s own starting estimate for recomposition. No study tests this exact rule.

Cut

2.4 g/kg LBM

Near the low end of Helms 2014: 2.3 to 3.1 g/kg LBM for lean, trained people in contest prep.

Sources: Jäger et al., ISSN position stand 2017; Morton et al., Br J Sports Med 2018 (meta-analysis); Helms et al., J Int Soc Sports Nutr 2014.

Four dosing rules, one calculator

The calculator uses one rule per goal. Each example shows how the rule compares with its closest source.

Recomposition (per kg LBM)2.2 × kg LBM65 kg LBM → 143 g. The calculator's own starting estimate; no study tests this exact rule.

Cut (per kg LBM)2.4 × kg LBM65 kg LBM → 156 g. Near the low end of the 2.3 to 3.1 g/kg lean-mass range Helms 2014 gives for contest prep.

Build (per kg BW)1.8 × kg BW, max 2.2 × kg LBM80 kg BW at 15% body fat → 144 g. Above the 1.62 g/kg break point in Morton 2018 and inside its 95% CI (up to 2.2).

Maintain (per kg BW)1.6 × kg BW, max 2.2 × kg LBM80 kg BW at 20% body fat → 128 g. Inside the 1.4 to 2.0 g/kg range the ISSN position stand (Jäger 2017) calls sufficient for most people who exercise.

LBM = lean body mass = weight × (1 − body-fat % / 100). Studies usually report fat-free mass (FFM), which is close to LBM. Without a body-fat input, the calculator assumes lean mass is 80 percent of body weight. Maintain and build targets never exceed the recomposition setting of 2.2 g per kg of lean mass, so at higher body fat they follow lean mass too. It then adjusts the target by +15 percent for advanced lifters and −5 percent for beginners; that adjustment is the calculator's own estimate.

The protein you think you're eating and aren't

Without logging, it is easy to overestimate how much protein a meal holds. The gap matters most in a calorie deficit.

The standard intuition is that any meal with chicken or eggs is a protein meal. The math says otherwise: a plate with 80 g of cooked chicken breast, two large eggs and a side salad has roughly 38 g of protein, not 60. Across three meals, a miss like that adds up.

Garthe et al. 2011 randomised 24 elite athletes, all strength training four times a week, to lose 0.7 or 1.4 percent of body weight per week. Lean mass rose 2.1 percent in the slower group and did not change in the faster group. The trial varied the pace of weight loss, not protein.

The fix is structural: pick a fixed protein dose for each main meal and check one week of meals against the daily total. How high that total should be depends on the goal. In the Morton 2018 meta-analysis, where people were not in a calorie deficit, extra protein stopped adding to training gains in fat-free mass at about 1.6 g per kg of body weight. For lean, trained people dieting for a contest, Helms 2014 recommends 2.3 to 3.1 g per kg of lean mass.

Protein and recomposition, explained

Six questions people search once protein stops being a number and starts being a tracked input.

References

Protein anchors the plate. These calculators turn the daily target into a full calorie budget, a macro split, and a body-composition target you can verify.

Macro Calculator

Slot protein in. Fat and carbs balance against TDEE automatically.

Lean Body Mass

The lean mass the dose is protecting. Track it monthly.

TDEE Calculator

Total maintenance to spend the protein dose against.

Body Fat Calculator

Recompute body fat to refresh the LBM the dose is scaled to.

Protein for body recomposition

How much protein a day for recomposition, cutting and bulking, with a worked example.

Body recomposition calculator

Estimate maintenance, a calorie and protein target, and a 12-week fat and lean-mass projection. Results depend on the model assumptions and your response.