Most people who lift weights need 1.2 to 1.7 grams of protein per kilogram of body weight each day to build muscle. For a 180-pound (82 kg) person, that works out to roughly 98 to 139 grams of protein daily. That range, recommended by Mayo Clinic, covers the needs of most resistance-trained individuals and endurance athletes. Going above 2 grams per kilogram per day is generally considered excessive and unlikely to produce additional muscle gains.
How to Calculate Your Target
Start by converting your body weight to kilograms (divide your weight in pounds by 2.2). Then multiply by 1.2 on the low end and 1.7 on the high end. Here’s what that looks like at common body weights:
- 140 lbs (64 kg): 77–109 g per day
- 160 lbs (73 kg): 88–124 g per day
- 180 lbs (82 kg): 98–139 g per day
- 200 lbs (91 kg): 109–155 g per day
- 220 lbs (100 kg): 120–170 g per day
Where you land in that range depends on training intensity and your goals. If you’re new to lifting or training three days a week, the lower end is sufficient. If you’re training hard five or six days a week and actively trying to add size, aim closer to 1.6 or 1.7 g/kg.
Why More Isn’t Always Better
A study from Harvard Health tracked older men who ate either 0.8 g/kg (the basic recommended dietary allowance for all adults) or 1.3 g/kg daily over six months. The higher-protein group showed no significant difference in lean body mass, muscle performance, or physical function compared to the lower-protein group. That study involved older adults without heavy resistance training, but it illustrates a broader principle: once you’ve hit your protein threshold, extra grams don’t translate into extra muscle.
The basic RDA of 0.8 g/kg is designed to prevent deficiency in sedentary adults. It’s not a muscle-building target. But jumping to 2.5 or 3 grams per kilogram won’t accelerate results either. Your body can only use so much protein for muscle repair at a time, and the surplus gets burned for energy or stored.
Higher Needs During a Calorie Deficit
If you’re trying to lose fat while preserving muscle, your protein needs go up. Research published in the International Journal of Sport Nutrition and Exercise Metabolism recommends 1.6 to 2.4 g/kg per day during a calorie deficit. Some studies on resistance-trained athletes suggest going as high as 2.7 g/kg during aggressive cuts, though the researchers note that intakes above 2.4 g/kg are unlikely to provide additional muscle-sparing benefits.
The logic is straightforward: when your body is short on calories, it’s more willing to break down muscle for energy. Higher protein intake acts as a buffer, giving your body enough amino acids to maintain existing tissue while you lose fat. This is the one scenario where pushing toward the upper end of the protein range makes a meaningful difference.
Spread It Across Your Meals
How you distribute protein throughout the day matters more than most people realize. Research shows that eating roughly 30 grams of protein at each meal stimulates 24-hour muscle protein synthesis more effectively than eating the same total amount in a lopsided pattern, like 10 grams at breakfast and 65 grams at dinner. That skewed pattern is how most people actually eat, loading protein into one large evening meal.
The sweet spot per meal appears to be 30 to 45 grams. Studies have found that this range produces the strongest association with leg lean mass and strength. Beyond about 30 grams in a single sitting, the rate of muscle protein synthesis plateaus. Your body doesn’t waste the extra protein, but it won’t use it for muscle building at the same efficiency. For someone targeting 130 grams daily, that’s roughly four meals with 30 to 35 grams each.
The Anabolic Window Is Overblown
You’ve probably heard that you need to slam a protein shake within 30 minutes of your last set. Two systematic reviews and meta-analyses found no beneficial effect of specific protein timing on muscle growth. A 2024 study in Frontiers in Nutrition confirmed this, concluding that total daily protein intake is “unquestionably the most crucial determinant in facilitating muscle growth induced by exercise,” regardless of when you eat it relative to your workout.
The so-called anabolic window likely extends over several hours, not the narrow 30-minute period that gym culture has popularized. If you ate a solid meal with 30 grams of protein an hour or two before training, your body still has plenty of amino acids circulating by the time you finish. A post-workout shake won’t hurt, but skipping it won’t cost you gains as long as your daily totals are on track.
Adjustments for Age
Nearly half of all protein in the body is found in muscle, and muscle mass naturally declines with age. This loss, called sarcopenia, starts as early as your 30s and accelerates after 60. Older adults appear to need a stronger protein signal to trigger the same muscle-building response that younger people get more easily. Researchers recommend that adults over 60 consume at least 1.0 to 1.2 g/kg per day even without heavy exercise, and likely more if they’re actively training.
Part of the issue is something called the leucine threshold. Leucine is the amino acid most responsible for flipping the switch on muscle protein synthesis. Younger adults can trigger that response with a lower dose, but older adults may need around 3 grams of leucine per meal. Since most protein sources contain about 10% leucine, that translates to roughly 30 grams of protein per sitting, reinforcing the per-meal guidance above.
Plant-Based Protein Considerations
Plant proteins are generally less digestible than animal proteins and often lack sufficient amounts of one or more essential amino acids, particularly lysine or methionine. This means that gram-for-gram, plant-based protein sources produce a smaller muscle-building response than animal sources like eggs, dairy, or meat.
The fix is straightforward: eat more total protein, combine different plant sources to cover amino acid gaps, or both. Rice and beans together, for example, provide a more complete amino acid profile than either one alone. Research from the Gatorade Sports Science Institute notes that most active athletes already eat well above 1.5 g/kg per day, and at that intake level, the lower quality of plant protein is unlikely to compromise muscle growth. If you’re plant-based and eating in a calorie deficit, though, protein quality becomes more important because you’re consuming less food overall, and every gram counts more.