How Much Protein Per Day Should I Eat?
Direct answer: If you lift weights or exercise hard most days of the week, eat 0.7 to 1.0 gram of protein per pound of body weight per day. A 170 lb lifter should aim for 120-170g. Sedentary adults can get away with the RDA of 0.36g per lb (roughly 60g for a 170 lb person), but that figure was set to prevent deficiency, not to optimize muscle, satiety, or body composition. Adults over 65 should hit at least 0.5g per lb whether or not they lift.
This is one of the most asked questions in fitness and one of the most badly answered. The official US RDA of 0.36g per lb (0.8g per kg) gets quoted endlessly, but that number was set in the 1970s to prevent symptomatic deficiency in sedentary adults. It is the protein equivalent of asking how much water you need to avoid dying of thirst. The modern question is different: how much protein optimizes muscle mass, recovery, satiety, and aging? The research consensus is much higher.
The Science: Where 0.7-1.0 g/lb Comes From
The most influential meta-analysis on protein and resistance training (Morton et al., 2018, British Journal of Sports Medicine) pooled 49 studies and found gains in lean mass and strength plateaued at roughly 1.6g per kg of body weight per day. That converts to about 0.73g per lb. Subsequent reviews (Schoenfeld and Aragon, 2018; Stokes et al., 2018) confirm that going higher than ~0.8g per lb provides no extra muscle benefit in studied populations, but the upper end (closer to 1.0g per lb) is recommended in two situations: aggressive fat loss diets, and lifters who have been training for many years.
If you want a single number to anchor on: 0.8 grams per pound of body weight per day covers nearly everyone who lifts. Below that you may leave gains on the table; above that you are not getting much extra in studies, though you may experience more satiety, which matters if you are cutting weight.
By Goal: What Should You Target?
Muscle gain (lean bulk)
0.8 to 1.0 g/lb of current body weight. The upper end is fine even in a calorie surplus. Spread across 3-5 feedings of 30-50g each.
Fat loss (cut)
1.0 to 1.2 g/lb of goal body weight (or current weight if you are not severely overweight). Higher protein on a cut preserves muscle and increases satiety. A 200 lb person dropping to 170 should target around 170-200g daily.
Maintenance / general health
0.5 to 0.7 g/lb. Enough to support training adaptations and aging-related muscle preservation without being excessive.
Sedentary adults
The RDA of 0.36 g/lb prevents deficiency. Most clinicians now recommend 0.5-0.7 g/lb even without exercise, especially after age 40, to defend against age-related muscle loss (sarcopenia).
How Much Protein Powder Does That Translate To?
Most people get 60-70% of their daily protein from whole food (eggs, meat, dairy, beans) and use a shake or two to close the gap. A typical scoop of whey concentrate delivers 24-25g of protein. Let's translate the targets into shakes per day for a 170 lb adult:
| Goal | Daily target | From food (typical) | Shakes to close gap |
|---|---|---|---|
| Sedentary | 90g | 70g | 1 scoop |
| Active maintenance | 115g | 80g | 1-2 scoops |
| Muscle gain | 140g | 90g | 2 scoops |
| Fat loss (cutting) | 180g | 100g | 3 scoops |
A 5 lb tub of Nutricost Whey delivers about 60 servings at 25g protein each. At two scoops per day that is a 30 day supply for around $33 on Amazon. If you are cutting and using three scoops, a 5 lb tub lasts 20 days. Worth knowing when you budget. See the live Value Score rankings for the cheapest current options.
Meal Timing: Does Distribution Matter?
Yes, modestly. Research on muscle protein synthesis (MPS) shows MPS spikes hardest when each meal contains at least 0.25-0.4 g/kg of protein, which is roughly 20-40g for most adults. Hitting four meals at 30-40g each tends to drive slightly more total daily MPS than two meals at 80g each. The effect size is small (5-10% in studies) but real. If you currently eat 30g at breakfast, 0g at lunch, and 90g at dinner, you will gain more muscle by redistributing to 40/40/40, even with the same total.
For a deeper dive see our protein per meal explainer and the timing myth versus reality post.
Common Mistakes
Mistake 1: Using bodyweight before counting fat. A very overweight adult should use a corrected weight (either lean body mass or goal weight), not raw scale weight. A 300 lb adult with 35% body fat does not need 240g of protein per day.
Mistake 2: Eating too much at one sitting. Most people can use roughly 0.4g per kg in a single feeding. Beyond that, surplus amino acids are oxidized for energy or stored, not used for muscle protein synthesis.
Mistake 3: Worrying about kidneys. In healthy adults, high protein intakes (up to 2.2g per lb in studies) have not been shown to harm kidney function. People with existing kidney disease should consult a clinician. See our full protein and kidneys explainer.
Mistake 4: Ignoring fiber. A 200g protein day with no vegetables is a fast track to gut problems. Protein and fiber go together.
What About Different Populations?
Women: Same g/lb math applies. Lower body weight typically means a lower absolute number. See our protein needs for women guide for pregnancy and postpartum specifics.
Adults over 65: Anabolic resistance means the same 30g meal triggers less MPS in older adults. Bump per-meal protein to 40g and total to at least 0.5-0.7 g/lb. See our seniors guide.
Vegetarians / vegans: Slightly higher target (10-15% above the omnivore number) because plant proteins generally have a lower digestibility score and lower leucine content per gram.
Quick Calculator (No Math)
Take your body weight in pounds. Multiply by 0.8 if you lift. By 0.5 if you are sedentary. By 1.0 if you are dieting hard. That is your daily protein target in grams. The result is rarely off by more than 10%, which is well inside the range studies show works.
If you want a more detailed answer based on your goals and activity, run it through our protein calculator. For shopping the cheapest powders that hit your daily target, see the 2026 cheapest whey ranking.