Your protein goal depends on your body weight and activity level. The simplest formula: multiply your body weight in kilograms by a number between 0.8 and 2.2, depending on your goals. For most people, that lands somewhere between 60 and 180 grams per day. The exact multiplier changes based on whether you’re sedentary, active, losing weight, or over 65.
The Basic Formula
Every protein recommendation uses the same structure: grams of protein per kilogram of body weight per day (g/kg/day). To find your weight in kilograms, divide your weight in pounds by 2.2. A 170-pound person weighs about 77 kilograms. A 200-pound person weighs about 91 kilograms.
Once you have your weight in kilograms, multiply it by the g/kg number that matches your situation. The government’s Recommended Dietary Allowance is 0.8 g/kg/day, which works out to about 0.36 grams per pound. For that 170-pound person, that’s roughly 62 grams of protein a day. But here’s the important nuance: the RDA represents the minimum needed to prevent deficiency, not the amount that’s best for health, muscle, or body composition. Think of it as a floor, not a target.
Ranges by Goal and Activity Level
Your ideal multiplier depends on what your body is doing right now.
- Sedentary adults: 0.8 g/kg/day is the baseline. For a 150-pound person, that’s about 55 grams.
- Generally active adults: 1.2 to 1.6 g/kg/day covers most recreational exercisers. For a 170-pound person, that’s 93 to 124 grams.
- Strength training for muscle growth: 1.6 to 2.2 g/kg/day is the range supported by sports nutrition organizations like the ISSN and ACSM. For that same 170-pound person, that’s 124 to 170 grams.
- Dieting or cutting calories: Protein needs actually go up when you eat less. During a caloric deficit, intakes of 1.6 to 2.2 g/kg/day help preserve muscle while you lose fat. During aggressive cuts combined with hard training, some athletes go as high as 2.3 to 3.1 g/kg of fat-free mass (not total body weight).
- Adults over 65: 1.0 to 1.6 g/kg/day is recommended to help slow age-related muscle loss. For a 180-pound older adult, that’s roughly 82 to 130 grams daily.
Step-by-Step Calculation
Here’s the process with a real example. Say you’re a 180-pound person who lifts weights three times a week and wants to build muscle.
Step 1: Convert pounds to kilograms. 180 ÷ 2.2 = 81.8 kg.
Step 2: Pick your multiplier. For muscle growth with resistance training, use 1.6 to 2.2 g/kg.
Step 3: Multiply. At the lower end, 81.8 × 1.6 = 131 grams. At the higher end, 81.8 × 2.2 = 180 grams.
Your daily protein target is 131 to 180 grams. If you’re also in a calorie deficit, aim toward the higher end. If you’re eating at maintenance calories and training moderately, the lower end is sufficient for most people.
If You’re Significantly Overweight
When body fat is high, using total body weight can inflate your protein target unnecessarily, since fat tissue doesn’t need protein the way muscle does. In that case, you have two options: calculate based on your goal weight instead of your current weight, or use your lean body mass if you have a rough estimate. If you weigh 260 pounds but estimate your lean mass at around 170 pounds, basing your calculation on 170 pounds gives a more practical number. Divide 170 by 2.2 to get 77 kg, then multiply by your chosen range.
How to Spread Protein Across Meals
Your body builds muscle most efficiently when protein is distributed throughout the day rather than loaded into one or two meals. Research points to roughly 0.25 to 0.4 g/kg per meal as the amount that best stimulates muscle repair. For most people, that translates to about 20 to 40 grams of protein per sitting, depending on body size.
If your daily goal is 150 grams, splitting it across four meals at roughly 35 to 40 grams each works well. Three meals of 40 grams plus a snack of 30 grams gets you there too. The key is avoiding a pattern where breakfast has 10 grams and dinner has 80. Spacing meals about three to four hours apart gives your body repeated signals to build and maintain muscle tissue throughout the day.
For older adults, hitting at least 25 to 30 grams per meal matters even more. Aging muscles need a stronger protein signal to kick-start repair. Research suggests that roughly 3 grams of leucine, an amino acid concentrated in animal proteins, dairy, and soy, is the threshold needed to fully activate muscle-building in older adults. A 20-gram portion of protein from most foods only provides about 2 grams of leucine, which falls short of that threshold. Bumping per-meal protein up to 30 to 40 grams closes that gap.
Adjustments for Plant-Based Diets
Plant proteins are generally digested and absorbed less completely than animal proteins. Grains, legumes, and vegetables score lower on protein quality scales that measure how well your body can use what you eat. This doesn’t mean plant protein is ineffective, but it does mean plant-based eaters may benefit from aiming toward the higher end of their recommended range to compensate. If your calculation says 1.6 g/kg, targeting closer to 1.8 or 2.0 g/kg gives you a buffer.
Variety also matters. Different plant proteins have different amino acid profiles, and combining sources throughout the day (beans with grains, tofu with nuts, lentils with rice) ensures you’re covering all the essential amino acids your body can’t make on its own. You don’t need to combine them in a single meal, just across the day.
Safety at Higher Intakes
For healthy people, high-protein diets have not been shown to cause medical problems. The concern about protein damaging kidneys applies specifically to people who already have kidney disease, because compromised kidneys struggle to filter the waste products of protein metabolism. If you have existing kidney disease or diabetes, higher protein intakes need to be discussed with a doctor. For everyone else, intakes in the 1.2 to 2.2 g/kg range are well within what the body handles without issue. Some researchers have flagged sustained intakes above 2.0 g/kg as worth being cautious about, not because of proven harm, but because long-term data at those levels is limited.