Protein supplies the amino acids your body uses to repair and grow muscle after training, so getting enough each day is essential for results. The research-backed sweet spot for building muscle is 1.6-2.2 grams of protein per kilogram of bodyweight per day (about 0.7-1.0 g per pound). Below roughly 1.6 g/kg you may leave gains on the table; above roughly 2.2 g/kg adds little extra benefit for most healthy people. This guide gives you the exact numbers, how to spread protein across the day, the best sources, and how to fit it into your calories using the TDEE Calculator and Meal Planner.
The Number: 1.6-2.2 g per kg of Bodyweight
Aim for 1.6-2.2 g of protein per kilogram of bodyweight daily to support maximal muscle growth. This range comes from meta-analyses of resistance-training studies (notably Morton et al., 2018), which find muscle and strength gains tend to plateau around 1.6 g/kg for most people, with a sensible upper margin near 2.2 g/kg.
Quick conversions (multiply your bodyweight in kg by 1.6-2.2):
- 60 kg (132 lb): 96-132 g/day
- 75 kg (165 lb): 120-165 g/day
- 90 kg (198 lb): 144-198 g/day
- 100 kg (220 lb): 160-220 g/day
In pounds, aim for roughly 0.7-1.0 g per pound of bodyweight. If you carry a lot of body fat, base the calculation on your target or lean bodyweight instead, since fat tissue contributes little to protein needs. The Body Fat Calculator can help you estimate lean mass. When in doubt, aim toward the top of the range (around 2.0 g/kg), especially while in a calorie deficit, to help protect muscle.
Protein Timing: Spread It Across the Day
Total daily protein matters most, but how you distribute it has a smaller, real effect. Aim for 3-5 meals containing roughly 25-40 g of high-quality protein each, spaced a few hours apart. This tends to keep muscle protein synthesis elevated through the day better than eating most of your protein in one or two large meals.
Practical guidelines:
- Target roughly 0.4-0.55 g/kg per meal (about 30-40 g for many adults) to fully stimulate muscle protein synthesis.
- The old "30-minute anabolic window" after training is largely a myth. A protein-containing meal within a few hours of your workout is plenty.
- A pre-sleep meal of 30-40 g (such as Greek yogurt or cottage cheese) may support overnight recovery.
Don't stress about precision. If you hit your daily total across several balanced meals, timing largely takes care of itself. Pair this with consistent resistance training like the barbell back squat and deadlift to give that protein a reason to build muscle.
Best Protein Sources for Muscle
The best muscle-building proteins are complete proteins that contain all nine essential amino acids, including leucine, a key trigger for muscle protein synthesis. Animal sources are naturally complete; if you eat mostly plants, combine a variety of sources and aim toward the higher end of the range.
High-quality options and approximate protein per serving:
- Chicken breast (100 g cooked): ~31 g
- Lean beef or pork (100 g cooked): ~26-30 g
- Eggs (2 large): ~12 g
- Greek yogurt, plain nonfat (170 g): ~17 g
- Salmon (100 g cooked): ~22-25 g
- Whey protein (1 scoop): ~24 g
- Firm tofu (100 g): ~8-12 g; lentils (1 cup cooked): ~18 g
Whole foods should form the base of your intake. Protein powder is a convenient supplement, not a requirement, useful when you're short on time or struggling to hit your target. Browse the Healthy Recipes library for high-protein meal ideas you can build a week around.
Fit Protein Into Your Calories
Protein works best inside the right overall calorie target. To build muscle, most people do well with a small calorie surplus of roughly 5-15% above maintenance, paired with progressive resistance training. A large surplus mostly adds fat rather than muscle.
Here's how to set it up:
- Find your maintenance calories with the TDEE Calculator, or estimate your baseline metabolic rate with the BMR Calculator.
- Set protein first (1.6-2.2 g/kg), then fill the rest of your calories with carbohydrates and fats to fuel training and recovery.
- Build your day's meals with the Meal Planner so you consistently hit both your calorie and protein targets.
Each gram of protein provides about 4 calories, so a 160 g protein target accounts for roughly 640 calories. Track your bodyweight trend over several weeks with the Weight Tracker and adjust calories up or down based on real progress rather than guesswork.
Common Mistakes to Avoid
Most people who struggle to build muscle make one of a handful of fixable errors around protein and training. Watch for these:
- Underestimating intake. People routinely think they eat more protein than they do. Track it for a few days to get an honest baseline.
- Chasing the anabolic window while ignoring the daily total, which matters far more.
- Over-doing protein well beyond ~2.2 g/kg expecting faster gains. Extra grams are unlikely to accelerate growth and mainly displace other useful calories.
- Eating enough protein but not training hard enough. Protein is the building material; progressive overload is the signal. Without challenging, progressive strength training, surplus protein is mostly used for energy rather than added muscle.
- Cutting protein during a fat-loss phase. When dieting, keep protein high (around 2.0-2.2 g/kg) to help preserve muscle.
Fix the training and the daily total first, and the rest is fine-tuning.
Key takeaways
- Eat 1.6-2.2 g of protein per kg of bodyweight daily (about 0.7-1.0 g per pound) to support maximal muscle growth.
- Spread protein across 3-5 meals of about 25-40 g each; total daily intake matters more than precise timing.
- Prioritize complete protein sources like chicken, eggs, dairy, fish, and whey; combine a variety of plant sources if vegetarian.
- Pair protein with progressive resistance training and a small calorie surplus (about 5-15% over maintenance).
- Keep protein high (around 2.0-2.2 g/kg) when cutting to help protect muscle during fat loss.
Frequently asked questions
How much protein do I need to build muscle?
Aim for 1.6-2.2 grams of protein per kilogram of bodyweight per day, or roughly 0.7-1.0 grams per pound. For a 75 kg (165 lb) person, that's about 120-165 grams daily. Most people see little extra muscle benefit above 2.2 g/kg.
Is more protein always better for muscle growth?
No. Muscle-building benefits tend to plateau around 1.6-2.2 g/kg of bodyweight. Eating beyond that is unlikely to speed up gains and mainly displaces other useful calories. Extra protein is largely used for energy, so going higher is unnecessary for most healthy people.
Does protein timing matter for building muscle?
Timing has a small effect compared to your daily total. Spreading protein across 3-5 meals of about 25-40 g each works well. The old 30-minute post-workout window is largely a myth; eating protein within a few hours of training is sufficient.
Do I need protein powder to build muscle?
No. Whole foods like chicken, eggs, dairy, fish, and legumes can fully cover your needs. Protein powder is a convenient supplement when you're short on time or struggling to hit your daily target, but it offers no special muscle-building advantage over food.
How much protein should I eat to lose fat while keeping muscle?
Keep protein high during a calorie deficit, around 2.0-2.2 g/kg of bodyweight, to help preserve muscle while losing fat. Combine this with resistance training. Use the TDEE Calculator to set your deficit and the Meal Planner to hit your protein target consistently.
Should I calculate protein based on total or lean bodyweight?
For most people, total bodyweight works fine. If you carry significant body fat, base the calculation on your target or lean bodyweight instead, since fat tissue contributes little to protein needs. Estimate your lean mass with the Body Fat Calculator for a more accurate target.