To calculate your daily protein intake, multiply your body weight in kilograms by a factor that matches your activity level and goals. The baseline formula is simple: body weight in kg × 0.8 = grams of protein per day. For a 150-pound (68 kg) person, that works out to about 54 grams. But 0.8 g/kg is the minimum for sedentary adults, and most people benefit from more.
The multiplier you use depends on whether you’re trying to maintain general health, build muscle, lose fat, or manage age-related changes. Here’s how to find your number.
The Basic Formula
Every protein calculation starts with the same two steps. First, convert your weight to kilograms by dividing your weight in pounds by 2.2. Second, multiply that number by a protein factor. If you prefer to skip the metric conversion, you can multiply your weight in pounds by 0.36 for the baseline recommendation.
That 0.8 g/kg figure is the Recommended Dietary Allowance set for healthy, sedentary adults. It represents the minimum amount needed to meet basic nutritional needs and prevent deficiency. It is not optimized for fitness, weight loss, or aging. Think of it as a floor, not a target. Most active people, older adults, and anyone with body composition goals will use a higher multiplier.
Protein Targets by Goal
Your ideal protein factor falls somewhere on a spectrum. Here’s where different goals land:
- General health, sedentary lifestyle: 0.8 g/kg (0.36 g/lb)
- Regular exercise, endurance or strength training: 1.2–1.7 g/kg (0.55–0.77 g/lb)
- Weight loss while preserving muscle: 1.6–2.4 g/kg (0.73–1.1 g/lb)
- Adults over 65: 1.0–1.2 g/kg (0.45–0.55 g/lb)
- Pregnancy or lactation: 1.1 g/kg (0.5 g/lb), or roughly 71 g/day
To put this in real numbers: a 180-pound (82 kg) person who lifts weights three times a week would multiply 82 × 1.2 on the low end and 82 × 1.7 on the high end, landing between 98 and 139 grams of protein per day. The same person trying to lose fat while keeping muscle would aim for 131 to 197 grams.
Why the Range Is So Wide for Weight Loss
When you eat in a calorie deficit, your body doesn’t just burn fat. It also breaks down muscle for energy. Protein counteracts this. The more aggressive your calorie cut and the more intensely you train, the more protein you need to protect lean mass.
Research on athletes cutting weight found that intakes of 1.6 to 2.4 g/kg per day were effective for preserving muscle, with some studies showing benefits up to 2.7 g/kg for resistance-trained individuals in steep deficits. Beyond about 2.4 g/kg, the additional muscle-sparing effect plateaus. So if you’re doing a moderate diet with light exercise, aim closer to 1.6 g/kg. If you’re combining heavy training with an aggressive cut, push toward the higher end.
Pairing higher protein with resistance training is particularly effective. This combination not only prevents muscle loss but can actually produce small gains in lean mass even during a calorie deficit.
Adjustments for Older Adults
Nearly half of all protein in the body is stored in muscle, and muscle mass naturally declines with age. This gradual loss, called sarcopenia, accelerates after 65 and increases the risk of falls, fractures, and loss of independence. Researchers now recommend that older adults consume 1.0 to 1.2 g/kg per day, which is 25 to 50 percent more than the standard RDA.
The official RDA for people over 65 is still set at 0.8 g/kg, the same as for younger adults. But a growing body of evidence suggests this is too low for maintaining muscle and function in aging bodies. The U.S. and Canada have launched a joint effort to update their Dietary Reference Intakes for protein, though new guidelines haven’t been finalized yet. In the meantime, the 1.0–1.2 g/kg range is widely supported by geriatric nutrition researchers. One exception: people with kidney disease should not increase protein without medical guidance, since the kidneys may struggle to process the extra waste.
Total Body Weight vs. Lean Body Mass
All the calculations above use total body weight. This works well for most people, but it can overestimate protein needs if you carry a significant amount of body fat. Fat tissue doesn’t require protein to maintain itself the way muscle does.
If your body fat percentage is above roughly 30 percent, consider using your goal weight or an estimate of your lean body mass instead. To estimate lean mass, subtract your body fat weight from your total weight. For example, a 220-pound person at 35 percent body fat carries about 77 pounds of fat and 143 pounds of lean mass. Using that 143 pounds (65 kg) as the basis for calculation gives a more accurate target. If you don’t know your body fat percentage, using your goal weight as the input is a reasonable shortcut.
How to Spread Protein Across the Day
Your body can only use so much protein at once to build and repair muscle. Studies show that about 30 grams of protein per meal is enough to maximize the muscle-building response. Eating 60 grams in one sitting doesn’t double the effect. The excess gets used for energy or other metabolic processes, but it won’t stimulate additional muscle repair.
This means spreading your protein across three to four meals tends to be more effective than loading it into one or two. If your target is 120 grams per day, four meals with 30 grams each will do more for muscle maintenance and growth than two meals with 60 grams. Research using nationally representative data from U.S. adults found that people who consistently hit at least 30 grams per meal had greater leg lean mass and knee strength compared to those who ate the same total amount but concentrated it at dinner.
Adjustments for Plant-Based Diets
If you get most or all of your protein from plants, you may need to aim slightly higher than the ranges listed above. There are two reasons for this. First, many plant proteins are missing or low in one or more essential amino acids. Grains tend to be low in lysine, while legumes are low in methionine and cysteine. Second, plant proteins are generally less digestible than animal proteins because of fiber, cell wall structures, and compounds that interfere with protein absorption.
You can compensate in two ways. Combine different plant protein sources throughout the day (beans with rice, tofu with whole grains) so the amino acid profiles complement each other. And consider bumping your target up by roughly 10 to 20 percent to account for the lower digestibility. A plant-based athlete aiming for 1.6 g/kg, for instance, might target 1.8 to 1.9 g/kg instead.
Is Too Much Protein Dangerous?
For healthy people, high-protein diets are not known to cause medical problems. The concern about protein damaging kidneys comes from clinical observations of people who already have kidney disease. In those cases, the kidneys struggle to filter the waste products of protein metabolism, and high intake can accelerate decline. But in people with normal kidney function, intakes well above the RDA have not been shown to cause harm.
That said, there’s a practical ceiling. Protein above about 2.4 g/kg per day doesn’t appear to provide meaningful additional benefits for muscle preservation or growth. Beyond that point, you’re just displacing calories that could come from carbohydrates and fats, both of which fuel training performance and support other body functions.