How Many G Of Protein Should I Have a Day? | By Weight

Most adults need 0.8 grams of protein per kilogram of body weight daily, though active people may require 1.2 to 2.0 g/kg depending on exercise.

One number gets thrown around a lot: 50 grams of protein per day. You see it on supplement labels, in magazine quizzes, and on social media posts about “enough” protein. The problem is that 50 grams might be too little for a 200-pound athlete and double what a 120-pound desk worker actually needs. Protein needs scale with body weight, activity, and life stage — not a single catch-all number.

This article walks through the science-backed way to find your personal daily protein target, using your weight as the starting point. You’ll see how the standard RDA fits a sedentary adult and how active people can adjust that number upward for muscle maintenance or growth.

The Classic RDA: 0.8 Grams Per Kilogram

The Recommended Dietary Allowance (RDA) for protein was set to prevent deficiency in nearly all healthy adults. That number is 0.8 grams of protein per kilogram of body weight per day. Per Harvard Health, this RDA for protein meets the needs of about 97% of sedentary individuals.

To find your baseline in grams, divide your weight in pounds by 2.2 to get kilograms, then multiply by 0.8. For a 150-pound adult, that’s about 55 grams per day. The American Heart Association also endorses this 0.8 g/kg target for adults 18 and older.

It’s worth noting that this is a floor, not a ceiling. The body uses roughly 300 grams of protein daily, but about 80% of that comes from recycling existing proteins — the diet just needs to replace what’s lost.

Why Your Daily Number Isn’t One-Size-Fits-All

Many people eat far more than the RDA without realizing it. NHANES data shows the average American man consumes about 102 grams of protein per day and the average woman about 70 grams — nearly double the baseline. Whether that extra protein is useful depends on your individual circumstances.

• Activity level: The International Society of Sports Nutrition recommends 1.4 to 2.0 g/kg for physically active individuals. Even moderate exercisers benefit from the 1.2 to 1.7 g/kg range suggested by the Food and Nutrition Board.
• Muscle-building goals: If you’re actively trying to gain lean mass, the upper end of the active range (1.6–2.0 g/kg) is commonly used. The extra amino acids support muscle protein synthesis after resistance training.
• Age and life stage: Growing children, pregnant women, and older adults have higher protein needs. The AHA notes that these groups require more than the standard adult RDA to support growth, fetal development, or to offset age-related muscle loss.
• Weight-loss goals: Higher protein intakes in the 1.2–1.6 g/kg range can promote satiety and preserve lean mass while in a calorie deficit, though individual targets vary.
• Health status: People recovering from surgery or illness sometimes need more protein temporarily. Kidney disease patients may need less — always follow your doctor’s guidance if a condition affects protein processing.

How Much Protein Do Active People Need?

Once you move beyond a sedentary lifestyle, the 0.8 g/kg baseline becomes a starting line, not a finish line. For someone who does moderate exercise three to five times a week, protein needs typically land between 1.2 and 1.7 g/kg. Serious athletes or those doing heavy resistance training often target 1.4 to 2.0 g/kg, per the ISSN position stand. Stanford Medicine confirms that for a 150-pound sedentary adult, 55 grams daily meets the RDA, but that number can double for active individuals of the same weight.

These ranges are general guidelines. Your actual needs depend on the intensity and type of exercise you do, as well as your overall calorie intake. The RDA prevents deficiency, but active people often need additional protein to support muscle repair and adaptation.

Calculating Your Personal Daily Target

Rather than guessing, you can find your number in about 30 seconds. Start with your weight in kilograms (pounds ÷ 2.2), then multiply by the appropriate factor from the ranges above. The result is a solid estimate you can use to plan meals.

1. Weigh yourself and convert to kilograms. A 180-pound person weighs about 81.8 kg. Write that number down.
2. Choose your activity factor. Sedentary: 0.8. Moderate exerciser: try 1.4. Heavy lifter: start at 1.6. Multiply your weight in kg by that number.
3. Spread protein across meals. Aim for 20–40 grams per meal depending on your target. That helps with satiety and muscle protein synthesis throughout the day.
4. Adjust based on results. If you’re not seeing expected energy, recovery, or muscle changes, try moving up within your activity range. Individual response varies.

What Does a Typical Day Look Like?

Hitting 55 grams of protein is manageable with standard portions: one large egg (6 g), a 3-ounce chicken breast (26 g), and a cup of Greek yogurt (20 g) already surpass it. Active targets like 120 grams require more intentional choices, such as adding a protein shake or an extra serving of lean meat at dinner.

The way you distribute protein also matters. Eating most of it in one sitting isn’t as effective for muscle protein synthesis as spreading it evenly across three or four meals. A simple approach is to include a protein source at each meal and snack.

Plant-based eaters can combine foods like beans and rice to form complete proteins, or rely on tofu, tempeh, lentils, and quinoa, which are already close to complete. Most people can meet their target without supplements, though a whey or plant protein powder can fill gaps conveniently.

The Bottom Line

Your daily protein number depends primarily on your body weight and activity level. The RDA of 0.8 g/kg is a solid baseline for sedentary adults, while active individuals typically benefit from 1.2–2.0 g/kg. There’s no single correct answer for everyone, but the range is well-studied and easy to calculate yourself.

If you’re unsure how your specific health conditions — kidney function, pregnancy, or a recent surgery — affect your needs, a registered dietitian can tailor the number to your full picture rather than relying on general charts.