How Much Protein Do You Need Per Day?

How much protein per day you actually need is not a single number. It depends on what you weigh and how active you are, and the honest answer is a range rather than a precise target. This guide walks through the official baseline, the higher amounts that active people and athletes need, and how to turn your own bodyweight into a daily target in grams. If you would rather skip the arithmetic, the Protein Calculator does the same maths for you in a few seconds.

What protein does in the body

Protein is the raw material your body uses to build and repair tissue. The protein you eat is broken down into amino acids, which are then reassembled into muscle, skin, hair, enzymes, hormones, antibodies, and the transport molecules that move oxygen and nutrients around. Unlike fat, the body has no large store of spare protein to draw on, so a steady daily supply matters. Nearly half of all the protein in your body sits in skeletal muscle, which is why intake and muscle maintenance are so closely linked.

When you eat too little protein over a long period, the body starts breaking down its own tissue, including muscle, to cover essential functions. That is the problem the official recommendation was designed to prevent.

The RDA: 0.8 grams per kilogram, and who it is for

The Recommended Dietary Allowance (RDA) for protein is 0.8 grams per kilogram of bodyweight per day for healthy adults. You can read the basis for this figure at the NIH MedlinePlus (Protein in diet). The important detail is what the RDA represents: it is the minimum needed to keep most healthy, mostly sedentary adults out of deficiency. It is a floor that prevents loss of body protein, not a target for someone trying to build muscle, train hard, or hold on to muscle while losing weight.

That distinction explains most of the confusion around protein. The RDA is correct and conservative for its purpose. It was simply never meant to describe the optimal intake for an active body. If you exercise regularly, the evidence points clearly higher.

Why active people need more

Resistance and endurance training both increase the rate at which muscle protein is broken down and rebuilt, and eating protein around training drives that rebuilding. The International Society of Sports Nutrition reviewed the evidence and, in its position stand on protein and exercise, concluded that a daily intake of 1.4 to 2.0 grams per kilogram of bodyweight is sufficient for most people who exercise to build and maintain muscle. For trained people dieting on fewer calories, even higher intakes of roughly 2.3 to 3.1 grams per kilogram of fat-free mass may help protect lean tissue.

How to compute your personal daily target

The calculation is simple. Take your bodyweight in kilograms, pick a number from the range that matches your activity, and multiply. If you think in pounds, divide your weight by 2.2 first to get kilograms.

1. Find your weight in kilograms (pounds divided by 2.2).
2. Choose a factor: about 0.8 if sedentary, 1.2 to 1.6 if generally active, 1.6 to 2.0 if training to build or keep muscle.
3. Multiply weight by the factor to get grams of protein per day.
4. Spread that total across the day, roughly 20 to 40 grams per meal, rather than in one sitting.

Factors that shift your number

A few situations move the target up. Older adults are one of the clearest cases. Muscle becomes harder to maintain with age, so many geriatric nutrition experts, including the PROT-AGE study group, recommend 1.0 to 1.2 grams per kilogram for healthy older people, and more during illness or recovery. Heavy training, a calorie deficit, and recovery from injury all push intake toward the upper end of the ranges above.

Pregnancy, breastfeeding, kidney disease, and other medical conditions change protein needs in ways that a general guideline cannot capture. If any of those apply to you, the number you want is the one a qualified professional gives you, not a formula.

A worked example

Take an adult who weighs 70 kilograms. At the RDA of 0.8 grams per kilogram, the baseline is 0.8 times 70, which is 56 grams of protein per day. That is enough to avoid deficiency if they are sedentary.

Now suppose the same person lifts weights three or four times a week and wants to build muscle. Using the ISSN range of 1.4 to 2.0 grams per kilogram gives 1.4 times 70, which is 98 grams, up to 2.0 times 70, which is 140 grams per day. A practical middle target of 1.6 grams per kilogram works out to 112 grams. So the same body can sit anywhere from 56 grams as a bare minimum to roughly 98 to 140 grams to support training, depending entirely on the goal.

To put 112 grams in context, that is about the protein in four eggs, a large chicken breast, a tin of tuna, and a serving of Greek yogurt spread across a day. It is reachable from food alone, which is worth remembering before reaching for supplements.

Rather than run these multiplications by hand every time your weight or training changes, enter your details once in the Protein Calculator and it returns a daily gram target for each activity level. From there you can read more on protein per kilogram of bodyweight, protein for muscle gain, and protein for weight loss.

The short answer

• 0.8 g/kg is the official minimum for healthy, sedentary adults, not an optimal goal.
• 1.4 to 2.0 g/kg suits most people who train and want to build or keep muscle.
• Older adults benefit from roughly 1.0 to 1.2 g/kg to protect against muscle loss.
• Pregnancy, illness, and kidney conditions need professional, individual advice.