Get the protein number thatkeeps your muscle while you lean out.
Most calculators hand you one number from a hidden formula. You get the evidence-backed range, where your goal lands you in it, an adjustment for how lean you already are, and the grams to hit at every meal. Enter your stats.
How a protein calculator works
Your daily protein target is a function of your bodyweight and your goal, not a fixed number. The 0.8 g/kg figure on nutrition labels is the RDA - a sedentary minimum to prevent deficiency. For anyone training or trying to change their body composition, the evidence-based range is 1.6 to 2.2 grams of protein per kilogram of bodyweight per day (ISSN position stand, Jager et al. 2017; Morton et al. 2018 meta-analysis).
Where you fall in that range depends on your goal. Building muscle in a calorie surplus sits near 1.6 g/kg, because gains plateau past that point. Cutting in a deficit pushes toward the high end - up to 2.3 to 3.1 g/kg of lean body mass (Helms et al. 2014) - to protect muscle while you lose fat. This tool also splits the total across your meals and checks each one against the roughly 0.4 g/kg per-meal leucine threshold that triggers muscle protein synthesis, so you see a real plan instead of a single daily total.
Common questions
How much protein do I need per day?
For most active adults the evidence lands at 1.6 to 2.2 grams of protein per kilogram of bodyweight per day (about 0.7 to 1.0 grams per pound) to build and hold muscle. The 0.8 g/kg RDA you see on food labels is a sedentary survival floor, not a performance target. The right number inside that band depends on your goal, your training, and how lean you already are - which is why this calculator shows you the range and where you fall in it, not one black-box number.
How much protein do I need to build muscle?
Resistance-trained gains plateau at roughly 1.6 g/kg of bodyweight per day, with the research confidence interval reaching about 2.2 g/kg (Morton 2018 meta-analysis; ISSN position stand). Eating well past that does not build extra muscle - it mostly displaces other calories. What matters more is hitting that target consistently and spreading it across meals so each one clears the leucine threshold that triggers muscle protein synthesis.
Is 1 gram of protein per pound too much?
No - 1 g per pound (about 2.2 g/kg) is at the high end of the evidence-based range, not above it. It is a safe, common target for people training hard or dieting, and it is easy to remember. It is more than most people strictly need to maximize muscle, but there is no muscle downside to it for healthy kidneys. If you carry higher body fat, basing the number on lean mass instead of total bodyweight keeps it from overshooting.
How much protein should I eat on a cut?
In a calorie deficit you should aim toward the HIGH end of the range to protect muscle while you lose fat. For lean dieters the research supports 2.3 to 3.1 grams per kilogram of lean body mass (Helms 2014). When you enter a body-fat percentage, this tool calculates on lean mass so a higher-body-fat person is not handed an unrealistically large number. The leaner and more aggressive the deficit, the higher in that band you go.
How much protein should I eat on Ozempic or another GLP-1?
GLP-1 medications like semaglutide and tirzepatide suppress appetite, so rapid weight loss on them often includes muscle unless protein and resistance training are prioritized. The practical move is to bias toward the high end of your protein range and front-load protein-dense foods early in the day before fullness sets in. This tool flags that and raises your target when you mark that you are on a GLP-1. It is educational only - your prescriber should guide your actual plan.