Guide · Protein
Protein Calculator: how to dose protein for body recomposition
A protein calculator gives you a single number in grams per day. This guide explains where the 1.6 to 2.2 g/kg band comes from, how to split it into meals, and why dropping below the floor in a cut burns the muscle you are trying to keep.
What the daily protein target represents
Protein intake is the single largest dietary lever for body recomposition. Every gram you eat above the floor protects existing muscle and feeds new muscle, every gram below it puts lean mass at risk. The protein calculator returns the daily gram target your body is asking for, anchored to weight, training load, and goal.
The target is a daily dose, not a per-meal rule. It is the total amount your body uses to repair muscle, replace tissue, and build new mass over 24 hours. How you split that total across the day decides how much of it actually lands as lean tissue.
Why the 1.6 to 2.2 g/kg band exists
Meta-analyses across resistance-trained populations land in the same range. Below 1.6 g/kg of body weight, lean mass retention drops measurably during a calorie deficit. Above 2.2 g/kg, the extra grams stop converting into more muscle and start displacing other macros. The band is not a guess, it is where the response curve plateaus.
The protein calculator places you inside that band based on your goal. A cut sits near the top of the range to defend lean mass against the deficit. A maintenance phase sits in the middle. A clean bulk sits lower in the band because the calorie surplus is doing more of the work.
How to use the calculator step by step
- 1. Enter your weight.Kilograms or pounds, whichever you actually weigh in. The formula scales the same way.
- 2. Pick your goal.Cutting, maintenance, or lean gain. The goal moves you up or down inside the 1.6 to 2.2 g/kg band so the daily dose matches what your body is doing.
- 3. Decide which weight to scale against.At healthy body fat, total body weight works fine. At higher body fat, scale to lean body mass instead. Fat tissue does not eat protein, so dosing the whole body weight overshoots. Use the lean body mass calculator first if your body fat is above 25 percent for men or 32 percent for women.
- 4. Read the daily gram total.The output is a single number in grams per day. That is your full daily protein dose, the budget every meal pulls from.
- 5. Split the dose across 3 to 5 meals.Muscle protein synthesis runs in pulses, not a constant drip. Spreading the total across three to five meals of 0.3 to 0.4 g/kg each keeps synthesis elevated all day. One huge meal cannot do the same job.
Per-kg of body weight vs per-kg of lean mass
The default protein formula scales to total body weight because most people do not know their lean mass. That works at healthy body fat. At 12 percent body fat, total weight and lean mass are close enough that the difference is small.
At 35 percent body fat, the gap is large. A 100 kg person at 35 percent fat carries 65 kg of lean mass. Scaling 2.0 g/kg to total weight returns 200 g per day. Scaling to lean mass returns 130 g. The first number is harder to hit, more expensive, and the extra protein is not protecting any tissue. The second number is what the body actually uses.
The rule: at healthy body fat, dose to total weight. Above 25 percent for men or 32 percent for women, dose to lean mass. The calculator handles either input. Once body fat drops back into the normal range, switch back to total weight.
Common mistakes using a protein calculator
- Dropping below the 1.6 g/kg floor in a cut. A calorie deficit without enough protein pulls the missing energy from muscle. The number on the scale moves, but the body composition gets worse. Hit the floor every day of the cut, even on rest days.
- Stacking all the protein into one meal. 200 g at dinner does not equal 50 g across four meals. The body uses what it needs in each pulse and oxidizes the rest. Spread the daily total across three to five doses of roughly equal size.
- Scaling to total weight at high body fat. If you are above 25 percent body fat as a man or 32 percent as a woman, dose to lean mass instead. Use the lean body mass calculator to get the right input, then feed it back into the protein target.
- Setting protein without setting the calorie budget. Protein is one slice of the day. The rest of the calories still have to balance against maintenance. Pair the protein target with a TDEE calculation and a macro split so the full day adds up.
Once you have the daily target, what to do with it
The daily gram total is the start of the plan, not the end of it. The next steps are splitting it into meals, choosing protein sources that hit those doses cleanly, and confirming the rest of the macros line up with your calorie target.
The Recomp AI protein calculator returns the daily gram total, the per-meal target across three to five doses, and links to the macros and TDEE calculators that complete the day. It is the shortest path from a protein number to a daily eating plan you can actually run.
Frequently asked questions
How much protein should I eat per day for body recomposition?
Between 1.6 and 2.2 grams per kilogram of body weight per day. Sit near the top of the band when cutting to protect lean mass, in the middle when maintaining, and at the bottom when in a calorie surplus. At high body fat, scale to lean mass instead of total weight.
Can I eat too much protein?
Above roughly 2.2 g/kg of body weight, the extra grams stop converting into muscle. They are not harmful for healthy kidneys, but they displace calories that could come from carbs or fats, and they cost more. The plateau is the upper edge of the useful range, not a hard limit on intake.
Does timing matter as much as total intake?
Total daily intake matters most. Distribution matters second. Spreading the total across three to five meals of 0.3 to 0.4 g/kg keeps muscle protein synthesis pulsing all day and outperforms two large meals at the same total. The post-workout window is wider than once believed, but a protein dose within a few hours of training is still useful.
Do I need a protein shake to hit the target?
No. Whole-food protein hits the same numbers. Shakes are a convenience for closing the gap when a meal is light or schedules get tight. If you can hit 1.6 to 2.2 g/kg from meat, fish, eggs, dairy, and legumes, no supplement is required.