How Much Protein Should a Person Consume In a Day?

The standard RDA is 0.8 grams per kilogram of body weight each day, but experts now recommend 1.2–1.6 g/kg for optimal health.

Most people assume there’s one magic protein number — maybe 50 grams, maybe 100. The truth is your daily target depends on your weight, your age, and how active you really are.

The official Recommended Dietary Allowance (RDA) sets a baseline of 0.8 grams per kilogram of body weight. That works out to roughly 46 grams for women and 56 grams for men. But a growing body of research suggests many adults benefit from more protein, especially as they get older or more active.

Understanding the RDA Baseline

The RDA for protein was designed to prevent deficiency in most healthy adults. According to the American Heart Association, the AHA protein recommendation set the number at 0.8 grams per kilogram of body weight for people ages 18 and older. That’s about 0.36 grams per pound.

For a 165-pound person (75 kg), the math works like this: 75 kg × 0.8 g = 60 grams of protein per day. This is the number most official dietary guidelines still use. It’s a sturdy floor — enough to keep your body’s basic protein needs covered.

But the RDA was never meant to be an optimal target for everyone. It answers the question “How little protein can you eat without getting sick?” not “How much protein supports your best health?”

Why Your Protein Question Isn’t One-Size-Fits-All

People ask about protein for different reasons — building muscle, losing weight, staying strong with age. Those goals change how much you need. Here’s what the research says about the biggest factors:

• Age matters a lot. Once you’re over 40–50, your body needs more protein to slow age-related muscle loss (sarcopenia). The RDA may not be enough for older adults.
• Activity level shifts the target. If you work out regularly or lift heavy weights, you’ll need more than the standard 0.8 g/kg. Athletes commonly aim for 1.2–2.0 g/kg.
• Your goal changes the number. Someone trying to build muscle will target the higher end of the range, while a person focused on weight maintenance may stay near the baseline.
• Body weight is the starting point. All protein recommendations are tied to your current weight, not your age or height. That’s why two 150-pound people with different goals can get different numbers.

Life stages also shift needs. Pregnant and breastfeeding women require extra protein to support fetal development and milk production.

Newer Guidelines Push the Needle Higher

In 2026, Stanford Medicine published revised dietary guidelines that moved the recommended range up to 1.2–1.6 grams per kilogram. That’s roughly double the old RDA for many people. Harvard Health walks through the reasoning on its protein per kilogram of body page, noting that the standard RDA was set decades ago and newer evidence supports higher intakes for muscle maintenance and overall health.

For a 150-pound person (68 kg), the new range means about 82–109 grams per day, compared to the old RDA of 54 grams. The shift matters most for adults over 50, who stand to lose muscle mass faster without adequate protein.

It’s important to note that the 1.2–1.6 g/kg range is an emerging consensus, not a universal guideline. The original RDA is still the official recommendation from many government agencies.

These numbers are starting points. If you’re very active or over 50, staying closer to the higher end of the range is often recommended.

How to Estimate Your Own Target

Use your weight and goals to find a practical number. Here’s a simple process:

1. Know your weight in kilograms. Divide your weight in pounds by 2.2. For example, 165 lbs ÷ 2.2 = 75 kg.
2. Multiply by 0.8 for the baseline. That gives you the minimum to prevent deficiency. For 75 kg: 60 grams.
3. Consider your age and activity. If you’re over 50 or exercise regularly, shift toward 1.2–1.6 g/kg. For the same person: 90–120 grams.
4. Check how much you’re already eating. NHANES data shows the average American man eats about 102 grams per day, and women about 70 grams — already above the RDA for most.
5. Spread protein across meals. Aim for about 20–40 grams per meal rather than loading up at dinner. This helps with satiety and muscle protein synthesis.

If you have kidney disease, check with a doctor before increasing protein. For most healthy people, up to 2 grams per kilogram is considered safe, but that upper limit isn’t a universal recommendation.

Is More Protein Always Better?

Not exactly. While many people could benefit from eating more protein, there’s an upper bound. UCLA Health states that most healthy people can safely eat up to 2 grams per kilogram, which for a 150-pound person is about 135 grams per day. But consistently exceeding that number may put strain on the kidneys over time, especially in people with existing kidney issues.

Stanford Medicine’s revised protein guidelines emphasize that the optimal range of 1.2–1.6 g/kg is supported by emerging research, but the evidence isn’t strong enough yet to replace the RDA as the official standard. Think of it as a well-supported upgrade, not a rule.

Spreading protein intake throughout the day is just as important as the total. Your body can only use so much at once; excess protein above your immediate needs is either stored as fat or excreted.

The Bottom Line

Your protein target isn’t a one-number answer. The RDA of 0.8 g/kg prevents deficiency, but many adults — especially those over 50 or regularly active — likely benefit from 1.2 to 1.6 grams per kilogram of body weight. Start with your weight in kilograms, multiply by your chosen target, and space the protein across meals.

If you have a medical condition like kidney disease or are pregnant, check with your doctor or a registered dietitian who can fine-tune your protein goal based on your bloodwork and specific activity level.