Protein is the most important macronutrient for building muscle, losing fat, and recovery. Find out exactly how much you need per day and per meal.
This protein calculator gives a general estimate and isn't medical advice. Individual needs vary based on health conditions, body composition, and specific training goals. Consult a healthcare provider or registered dietitian for personalized guidance.
For most adults pursuing fat loss or muscle gain, the evidence-backed protein target is 0.7 to 1.0 grams per pound of goal body weight (1.6-2.2 g/kg). On a GLP-1 like semaglutide or tirzepatide, hitting protein protects lean mass, patients who fall short can lose 25-40% of weight from muscle. Older adults (50+) need the higher end of the range due to anabolic resistance.
Source: Morton RW et al. Br J Sports Med 2018 · ISSN protein position standProtein is the most important macronutrient you put in your body. That's not hyperbole, it's chemistry. Protein is the only macronutrient the body can't store in a meaningful way, the only one required to build and repair tissue, and the only one that reliably produces measurable improvements in body composition, satiety, and metabolic rate when you eat more of it.
Unlike carbs (which can be stored as glycogen) or fat (which can be stored essentially indefinitely), your body has no protein reserve. If you don't eat enough, it breaks down muscle to get what it needs. That's why under-eating protein is one of the fastest ways to lose muscle, slow your metabolism, and undermine nearly every other goal you're working on.
Whether your goal is fat loss, muscle gain, healthier aging, or just feeling satisfied after meals, protein is the lever that moves the most.
The RDA (Recommended Dietary Allowance) for protein in adults is 0.36 grams per pound of bodyweight (0.8 g/kg). That number, set by the Institute of Medicine, is the minimum required to prevent deficiency in sedentary adults. It's not the amount needed for health, performance, or body composition.
Modern sports nutrition and aging research consistently show that the optimal intake for most active adults is 2 to 4 times the RDA. Here's the breakdown:
| Goal | Protein (g/lb) | Protein (g/kg) |
|---|---|---|
| Minimum to prevent deficiency | 0.36 | 0.8 |
| Sedentary maintenance | 0.5-0.7 | 1.1-1.5 |
| General fitness / active | 0.7-0.9 | 1.6-2.0 |
| Building muscle | 0.8-1.0 | 1.8-2.2 |
| Fat loss (preserving muscle) | 1.0-1.2 | 2.2-2.6 |
| Advanced / competition lean | 1.2-1.5 | 2.6-3.3 |
For most men and women with general fitness goals, the sweet spot is 0.8-1.0 grams per pound of goal bodyweight. For a 180-lb man targeting 170 lbs, that's 136-170 grams of protein per day. For a 140-lb woman targeting 130 lbs, it's 104-130 grams per day.
For fat loss specifically: higher protein intake is one of the single most important factors in preserving muscle during a calorie deficit. If you're cutting calories and not hitting 1.0+ g/lb of goal bodyweight, you're losing more muscle than necessary.
Our calculator combines your body weight, activity level, and goal to produce a daily protein target that reflects current sports nutrition research:
The result is a daily target in grams that's realistic, not extreme. If your calculator result feels high, that's because most people have been under-eating protein their whole lives. The standard American diet produces about 0.4-0.6 g/lb, consistently below optimal.
Not all protein is created equal. Two factors determine quality: amino acid profile (does it contain all nine essential amino acids in the right ratios?) and leucine content (the amino acid that triggers muscle protein synthesis).
~6 g per egg. The "gold standard" for amino acid profile, every other protein is often compared to eggs.
~25 g per 3 oz. Lean, neutral-flavored, easy to batch cook. The default for most people pursuing body composition.
~22 g per 3 oz. Sirloin, 93/7 ground beef, or flank steak. High in heme iron, zinc, and B vitamins.
~20-25 g per 3 oz. Salmon adds omega-3 fats; cod and tuna are leaner protein bombs with very few calories.
~17 g per 6 oz (plain, 0% or 2%). Best bang-for-buck dairy source. Avoid "fruit on the bottom" versions.
20-25 g per scoop. Whey absorbs fast (best post-workout); casein absorbs slow (best before bed).
Most plant proteins are "incomplete" (missing or low in one or more essential amino acids) and have lower leucine content. This means vegans and vegetarians need somewhat more total protein, and variety is key.
The hype about protein timing has outpaced the research. The original idea, that you must consume protein within 30-60 minutes of a workout to capture the "anabolic window", has been softened substantially. Here's what the current evidence says:
If you're hitting your total protein target for the day, the timing of individual meals has a relatively minor effect. Total intake explains the majority of the results.
Research on muscle protein synthesis shows you get a bigger muscle-building response from 4 evenly-spaced protein feedings of 30-50 g than from 1-2 very large feedings totaling the same amount. The "leucine threshold", roughly 2.5-3 g of leucine per meal, is the trigger that maximizes muscle protein synthesis.
Practical implication: aim for 3-5 meals spaced 3-4 hours apart, each containing at least 25-40 g of protein.
A slow-digesting protein (casein, cottage cheese, or Greek yogurt) 30-60 minutes before sleep has been shown to support overnight muscle protein synthesis and improve recovery, especially in people training hard.
Eat a protein-containing meal within 2 hours before and 2 hours after training for the best recovery response. The timing doesn't need to be exact; the "window" is wider than the old advice suggested.
The simplest rule: four meals with 30-40 g of protein each hits nearly every target, total daily intake, distribution, and leucine threshold, without needing a spreadsheet.
Higher protein during a calorie deficit is one of the most well-established findings in nutrition research. It reduces muscle loss, increases satiety, and raises the thermic cost of eating. Target 1.0-1.2 g per pound of goal bodyweight. If you're on a GLP-1 medication, protein becomes even more important, reduced appetite makes it easy to miss target, and GLP-1 users lose a significant fraction of weight as muscle without high protein intake.
Contrary to popular belief, you don't need extreme protein intake to build muscle, 0.8-1.0 g per pound is sufficient for most natural lifters. Above ~1.2 g/lb, research shows diminishing returns. Total calories, progressive overload in training, and sleep matter more than adding another scoop of whey.
Older adults develop "anabolic resistance", their muscles respond less efficiently to dietary protein. To compensate, people over 60 typically need 0.5-0.7 g per pound minimum, with emphasis on high-quality, leucine-rich sources. Combined with resistance training, this protects against sarcopenia (age-related muscle loss) and preserves independence.
Runners, cyclists, and triathletes need more protein than sedentary people, 0.6-0.8 g per pound, to support recovery from high training volume. Endurance training breaks down muscle; adequate protein rebuilds it.
Adequate protein intake is associated with preserved lean mass, better metabolic health, and reduced frailty into older age. The lowest-protein diets are linked to worse outcomes, not the other way around. Use our NAD+ article and other longevity content for additional context.
Short answer: for healthy adults, no.
The belief that high protein intake "damages your kidneys" is one of the most persistent myths in nutrition. It comes from a valid concern, that people with existing kidney disease should moderate protein intake. That concern was then wrongly generalized to healthy adults.
In healthy kidneys, research has shown no harm from intakes of up to 2.0+ g per pound of bodyweight. That's roughly 4-5x the RDA. Your body simply metabolizes excess protein for energy or excretes the nitrogenous byproducts through urine, no strain, no damage.
For a healthy adult, the much bigger risk is under-eating protein, which almost everyone does, not over-eating it.
No. For healthy adults, intakes of up to 2.0 g per pound have been studied with no adverse effects. There's just a point of diminishing returns for muscle building, generally around 1.0-1.2 g/lb. Eating more isn't harmful; it's just unnecessary for most goals.
This is a myth. Your body absorbs essentially all the protein you eat, just at different rates. The "30g limit" came from research on muscle protein synthesis, which does plateau around 30-40 g per meal for young men. That's about muscle-building signaling, not absorption. A 60 g meal fully digests; it just doesn't stimulate more muscle synthesis than a 40 g meal would.
For muscle protein synthesis specifically, yes. Whey protein is actually one of the highest-quality protein sources by amino acid profile and leucine content. But whole foods come with other benefits (micronutrients, fiber, satiety) that powder doesn't. Use powder as a convenience tool, not a meal replacement.
Absolutely. It just requires attention to total intake and amino acid quality. Aim ~10-15% higher on total protein to offset lower leucine density in plants. Combine sources, soy + grains, beans + rice, legumes + nuts, to cover all essential amino acids. A pea + rice protein blend closely mimics whey's amino acid profile.
On a per-pound basis, yes. Women may actually benefit more from high-protein intake in some contexts, particularly during peri-menopause and menopause, when protein needs rise as estrogen protects muscle less. The outdated idea that women need less protein is tied to the equally outdated idea that women shouldn't lift weights.
Not urgently. The "anabolic window" is wider than old advice suggested, eating a protein-rich meal within 2-3 hours before or after training is fine. Total daily intake and distribution across meals matter far more than exact post-workout timing.
It can if you ramp up too fast. Bloating is usually from digestive enzymes needing time to adjust, not a sign of harm. Scale up protein intake over 2-3 weeks, stay hydrated, and spread it across 3-5 meals. If bloating persists, check for intolerance to specific sources (dairy is a common culprit, try whey isolate or a non-dairy powder).
No, the opposite. Older research suggesting protein "leached calcium from bones" was wrong. Recent meta-analyses show high-protein diets are associated with better bone density and lower fracture risk, particularly in older adults. Combined with adequate calcium and resistance training, protein supports bone health.
Protein is the lever for muscle. These tools cover the rest of the system, calories around your protein target, body composition, and the hormones that determine whether your protein actually builds tissue.
Hand-picked guides on protein, muscle gain, recovery, and how to actually translate grams-per-pound into body composition change.
On semaglutide and tirzepatide, 25-40% of weight lost can come from lean mass, unless you hit protein. Patients who clear their protein target lose roughly 30% less muscle. That's the difference between looking lean and looking depleted. Pair your protein number with the right GLP-1 protocol.
How this tool calculates
Daily protein targets are calculated per the International Society of Sports Nutrition (ISSN) position stand: 1.4-2.0 g/kg/day for active individuals to support muscle mass and recovery; higher ranges (2.3-3.1 g/kg) for those in a caloric deficit or aging adults to preserve lean tissue.
Peer-reviewed sources
Important. This tool is provided for educational purposes only and does not constitute medical advice, diagnosis, or treatment. The tool does not prescribe medication, recommend specific dosing, or substitute for clinical evaluation. Compounded medications referenced anywhere on this site are not FDA-approved; the FDA does not verify the safety, effectiveness, or quality of compounded drugs. Treatment decisions are made only by a licensed U.S. physician after individual patient evaluation.