The honest answer to "how much protein" is a range, not a number, and it starts with your body weight. The National Academies' RDA is 0.8 grams per kilogram, a floor designed to prevent deficiency in sedentary adults. Sports nutrition research puts muscle-building needs at 1.6 to 2.2 g/kg. For a 180 lb (82 kg) person, that's the difference between 65 g and 131–180 g a day, and both answers are correct for different lives.
Multiply your weight in kilograms by the multiplier that matches your life, and you're done. Here's the table for five common weights:
| Body weight | RDA 0.8 g/kg | Active 1.2 g/kg | Muscle 1.6 g/kg | Muscle 2.2 g/kg |
|---|---|---|---|---|
| 120 lb (54 kg) | 44 g | 65 g | 87 g | 120 g |
| 150 lb (68 kg) | 54 g | 82 g | 109 g | 150 g |
| 180 lb (82 kg) | 65 g | 98 g | 131 g | 180 g |
| 210 lb (95 kg) | 76 g | 114 g | 152 g | 210 g |
| 240 lb (109 kg) | 87 g | 131 g | 174 g | 239 g |
The 0.8 g/kg column keeps a sedentary adult out of deficiency. Every other column assumes you're asking something of your body: walking a lot, running miles, or lifting. Our protein intake calculator does this math for any weight and adds per-meal splits and food equivalents.
Enter your weight and goal, see your daily range, per-meal amount, and how much chicken that actually is.
Protein Intake Calculator →It's not wrong, it's narrow. The RDA was set as the minimum that prevents a protein deficiency in nearly all healthy sedentary adults, and at that job it works. But a large body of research since then shows better outcomes above it: adults over 65 preserve muscle better at 1.0 to 1.2 g/kg (the recommendation of geriatric nutrition societies like ESPEN), and exercising adults benefit from 1.2 to 2.0 g/kg per sports dietitian position stands.
Think of 0.8 g/kg as the wage that keeps the lights on. The higher ranges are what you pay a body that's training, recovering, aging, or holding onto muscle in a calorie deficit.
The most-cited answer comes from a 2018 meta-analysis of 49 resistance training studies (Morton and colleagues, British Journal of Sports Medicine), which found muscle gains plateaued around 1.6 g/kg with a confidence interval stretching to about 2.2. Translation: eat somewhere in 1.6–2.2 g/kg and you've captured nearly all the benefit protein can give a growing bicep.
Per meal, the research habit is 0.4 g/kg across 4 meals or 0.55 g/kg across 3. An 80 kg lifter lands at roughly 30 to 45 g per sitting, which is one cooked chicken breast or a cup of Greek yogurt plus a scoop of whey. Past that per-meal size, extra protein isn't wasted exactly, but the muscle-building response doesn't climb much further.
Yes, and it's the most underused diet trick there is. A calorie deficit makes your body willing to burn protein for fuel, so the same workout stimulus protects less muscle unless you raise intake. During a cut, 1.6 to 2.4 g/kg is the commonly cited range, with leaner people toward the top. Protein is also the most satiating macro per calorie: it quiets hunger in a way that 200 calories of crackers never manages.
| Food | Serving | Protein |
|---|---|---|
| Chicken breast, cooked skinless | 100 g | 31 g |
| Ground beef 90%, cooked | 100 g | 26 g |
| Salmon, cooked | 100 g | 25 g |
| Egg, large | 1 | 6 g |
| Greek yogurt, nonfat | 170 g cup | 17 g |
| Lentils, cooked | 100 g | 9 g |
| Whey powder | 1 scoop | 24 g |
A 155 g target for a 180 lb lifter breaks down as: eggs and yogurt at breakfast (~28 g), a chicken-and-rice lunch (~40 g), a whey shake as an afternoon snack (~24 g), and salmon with dinner (~35 g), with odds and ends from grains and vegetables making up the rest. It's structured, not heroic.
For healthy kidneys, the evidence says no: controlled trials and reviews have not found harm up to about 2.2 g/kg, and a 2018 review of protein intake in athletes concluded exactly that. The caution is real for chronic kidney disease, single kidneys, and some liver conditions, where limits are individualized. If any of those apply, your nephrologist's number replaces every table on this page.
Start from weight, adjust for demand. Sedentary: 0.8 g/kg. Over 65 or moderately active: 1.0–1.2. Endurance: 1.2–1.4. Lifting or cutting: 1.6–2.2 (or 2.4 in a hard deficit). Split it over 3–4 meals and let the rest of the day be carbs and fat. To turn those calories into full macros, the macro calculator divides your intake by goal, and the calorie calculator finds the total those macros come from.
It depends on your size. 100 g covers the RDA for anyone up to about 275 lb and comfortably hits athletic ranges under 140 lb. For a 180 lb person training hard, 100 g sits below the 131 to 180 g research range for building muscle, though it's still far better than average.
Yes, when total protein and total leucine are matched, plant and animal sources support similar muscle gains in most trials. The practical catch is density: 100 g of cooked lentils carries 9 g of protein while 100 g of chicken carries 31 g, so plant-based lifters usually plan portions more deliberately and may lean on soy, seitan, and protein powder.
Less than once believed. Total daily protein is the main lever; the anabolic window after a workout is real but wide, several hours, not thirty minutes. What does matter is distribution: hitting roughly 0.4 g per kg at 3 to 4 meals beats front-loading or back-loading the same total.
In healthy adults, extra protein beyond about 2.2 g per kg mostly gets burned for energy or stored as fat, not built into muscle. The bigger practical risks are crowding out other foods and, in people with existing kidney disease, adding load the kidneys can't spare. Protein powder overdoses are expensive urine before anything else.