How Much Protein You Actually Need Per Day
Your daily protein target depends on whether you are maintaining, building, or dieting, and the three answers are meaningfully different.
Quick answer: Most adults need roughly 0.6 to 0.9 grams of protein per pound of body weight per day, or 1.3 to 2.0 grams per kilogram. A 165 lb (75 kg) person therefore lands somewhere between about 100 and 150 grams. Sit at the bottom of that band if you are sedentary, and near the top if you lift weights or are eating in a calorie deficit.
The official minimum, the RDA, is 0.8 grams per kilogram, which works out at 0.36 grams per pound. That figure gets quoted constantly and it is not wrong, but it answers a narrow question: how little protein can a person eat before they start losing tissue. Most people want something else. They want to hold onto muscle, build some, or stop being hungry at 4pm.
The number changes with what you are asking protein to do
Protein has three jobs that matter here. It builds and repairs muscle. It keeps you full, which is why the same calorie total is easier to live with when more of it arrives as protein. And it protects lean mass when you are eating less than you burn, which is where undereating protein does the most damage.
Maintenance, building, and dieting are three different targets
If you are not training and your weight is steady, 0.6 g per pound is plenty. If you are lifting three or more times a week and want the muscle to show up, 0.7 to 0.8 g per pound covers it. If you are in a deficit, push to 0.9 g per pound, because a bigger share of the weight you lose will otherwise come off as muscle rather than fat.
Above roughly 1 gram per pound the returns flatten out. That surprises people, since 1 g per lb has been a gym staple for thirty years. It is a fine round target, just not a magic one.
Run your own numbers
It is free, there is no sign-up, and it works on your phone.
Open the Protein CalculatorTwo examples, worked all the way through
A 165 lb office worker who lifts three mornings a week: 165 x 0.7 = 116 grams. Split over three meals that is 39 grams a meal. A 6 oz cooked chicken breast is about 50 g, a 170 g pot of Greek yoghurt about 17 g, and two eggs about 12 g. One solid protein source per meal plus a snack gets there without any powder.
A 200 lb person cutting on 2,000 calories a day: 200 x 0.9 = 180 grams. Protein carries 4 calories per gram, so that is 720 calories, or 36 per cent of the day's intake, before any fat or carbohydrate at all. This is where most people discover their diet is harder than they thought. If your protein target eats more than about 40 per cent of your calories, either the deficit is too aggressive or the protein number is.
In metric, a 68 kg woman training for strength at 1.8 g/kg needs 122 grams a day.
Try it with your figures
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Use the Protein CalculatorHow to use the protein calculator
Enter your weight, pick an activity level, and choose a goal. The calculator returns a daily gram target and usually a range around it. The range is the part that matters. Anywhere inside it is fine, and hitting 130 g against a 140 g target is not a failed day.
Where to find the inputs
Weight is whatever the scale says in the morning, not your goal weight. Activity level here means resistance training sessions per week, not step count. Goal is maintain, lose, or gain. If you already know your calorie ceiling, set protein first and let the other two macros fill the gap, which is the order used in calculating your macros. In a gaining phase the calorie side matters more once you are past about 0.8 g per pound, and setting TDEE for muscle gain handles that half.
Common questions
Should I use my current weight or my goal weight? Current weight, unless you are carrying a lot of fat. Someone at 300 lb aiming for 200 lb does not need 270 grams of protein. Use goal weight or lean body mass in that case, which lands nearer 180 grams.
Can you eat too much protein? For people with healthy kidneys there is no defined upper limit, and the ceiling you hit first is appetite and grocery budget rather than organ function. A 200 lb person is already at 180 grams on the 0.9 figure above; going past 250 means every meal has to be built around a protein source before anything else goes on the plate, which most people abandon within a fortnight. Anyone with kidney disease should get a target from their doctor, not a calculator.
Does it matter how much protein I get per meal? A bit. Three or four meals of 30 to 40 grams beats one 120 gram dinner, but only slightly. Fix the daily total first and worry about timing later.
Do I need protein powder? No. It is convenient and cheap per gram, which is the whole argument for it. A scoop is typically 24 grams for 120 calories, hard to match with food when you are 30 grams short at 9pm.