Protein Calculator
Calculate your optimal daily protein intake based on weight, goals, and activity level. Includes meal distribution, food equivalents, and timing recommendations.
Medical Disclaimer: This calculator provides general protein intake guidelines. Individual needs vary based on health conditions, medications, and specific goals. Consult a registered dietitian or healthcare provider for personalized nutrition advice.
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About This Calculator
"How much protein do I need to build muscle?" It's the question at the heart of every fitness conversation—and the answer varies more than you might think. The generic "just eat 1 gram per pound of body weight" advice is overly simplified, and the government's RDA of 0.36g/lb is designed to prevent deficiency, not optimize performance.
Here's what the research actually shows: Your optimal protein intake depends on your specific goal. Someone in a caloric deficit trying to preserve muscle needs significantly MORE protein than someone in a surplus trying to build it. An athlete training twice a day has different needs than a recreational gym-goer. A 60-year-old needs more protein than a 25-year-old to maintain the same muscle mass.
The science is clear on this: A landmark 2018 meta-analysis published in the British Journal of Sports Medicine found that protein intakes of 1.6-2.2 grams per kilogram of body weight optimize muscle building in resistance-trained individuals. But during fat loss phases, research suggests going even higher—up to 2.5g/kg—to preserve muscle in a caloric deficit.
Here's what nobody tells you: Protein isn't just about muscles. Adequate protein reduces age-related muscle loss (sarcopenia), improves bone density, supports immune function, helps regulate appetite hormones, and has the highest thermic effect of any macronutrient—meaning you burn more calories just digesting it.
This Protein Calculator uses evidence-based formulas from sports nutrition research to provide personalized recommendations based on your weight, goals, activity level, and training type. You'll see your target in grams, what that looks like in real food, how to distribute it across meals for optimal muscle protein synthesis, and timing recommendations based on your specific situation.
Whether you're a bodybuilder calculating macros, someone trying to lose fat without losing muscle, a vegetarian figuring out plant-based options, or just wondering if you're eating enough protein for general health—this calculator gives you science-backed numbers instead of bro-science guesses.
Note: Individuals with kidney disease should consult a physician about protein intake. For everyone else, protein intakes up to 2.5g/kg have shown no adverse effects in research.
Trusted Sources
How to Use the Protein Calculator
- 1**Select your measurement system:** Choose Imperial (pounds) or Metric (kilograms) based on how you typically track your weight.
- 2**Enter your body weight:** Input your current weight. For most accurate results, weigh yourself first thing in the morning after using the bathroom, and use a weekly average rather than a single day.
- 3**Select your primary goal:** This is the biggest factor affecting protein needs. Building muscle requires high protein; fat loss while preserving muscle requires VERY high protein; general health needs moderate amounts.
- 4**Choose your activity level:** Higher activity creates more muscle breakdown and repair, increasing protein demands. Be honest—most people overestimate their activity level.
- 5**Select your training type:** Resistance training (weight lifting) creates the highest protein demands. Endurance training increases needs moderately. No training requires less protein.
- 6**Review your personalized results:** See your daily target in grams, what that looks like in food equivalents, how to split it across meals, and timing recommendations for your goal.
- 7**Adjust based on body fat (optional):** If you know your body fat percentage, the calculator can use lean body mass for more accurate recommendations—especially important if you have high body fat.
Formula
**Protein Requirement Formulas:**
**By Body Weight (General):**
```
Daily Protein (g) = Body Weight (kg) × Multiplier
```
| Goal | Multiplier (g/kg) | Multiplier (g/lb) |
|------|-------------------|-------------------|
| RDA Minimum | 0.8 | 0.36 |
| General Fitness | 1.0-1.2 | 0.45-0.55 |
| Muscle Building | 1.6-2.2 | 0.73-1.0 |
| Fat Loss | 2.0-2.5 | 0.9-1.1 |
| Older Adults | 1.2-1.5 | 0.55-0.68 |
**By Lean Body Mass (More Accurate):**
```
Daily Protein (g) = Lean Body Mass (kg) × 2.2-2.8
```
*Use this if you know your body fat percentage.*
**Example Calculation:**
180 lb person (82 kg) wanting to build muscle:
- Using body weight: 82 kg × 1.8 = 148g protein/day
- Range: 82 × 1.6 to 82 × 2.2 = **131-180g/day**
**Per Meal Distribution:**
```
Protein Per Meal = Daily Target ÷ Number of Meals
```
Minimum per meal for MPS: 20g (young adults) or 25-30g (older adults)These formulas are derived from sports nutrition research, particularly the 2018 meta-analysis by Morton et al. and position stands from the International Society of Sports Nutrition (ISSN). **Key Points:** - The RDA of 0.8g/kg is a minimum to prevent deficiency—not optimal for active individuals - Higher protein needs during fat loss protect muscle mass during caloric deficit - Older adults need more protein due to reduced anabolic response to protein (anabolic resistance) - Lean body mass calculations are more accurate for those with high body fat percentages **Individual Variation:** These are evidence-based ranges. Individual needs vary based on genetics, training intensity, sleep quality, stress, and other factors. Use the calculator results as a starting point and adjust based on your results over 2-4 weeks.
Protein Requirements: What Science Actually Says
Protein recommendations have evolved significantly as sports nutrition research has advanced. Here's what current evidence supports:
Protein Intake by Goal (grams per kg of body weight):
| Goal | Protein (g/kg) | Protein (g/lb) | Evidence Base |
|---|---|---|---|
| RDA (Minimum) | 0.8 | 0.36 | Prevents deficiency, not optimal |
| General Health | 1.0-1.2 | 0.45-0.55 | Active adults, health maintenance |
| Recreational Exercise | 1.2-1.6 | 0.55-0.73 | Regular gym-goers, casual athletes |
| Muscle Building | 1.6-2.2 | 0.73-1.0 | Resistance training, hypertrophy goal |
| Fat Loss (preserve muscle) | 2.0-2.5 | 0.9-1.1 | Caloric deficit phase |
| Endurance Athletes | 1.2-1.6 | 0.55-0.73 | Marathon, cycling, swimming |
| Elite Athletes | 1.8-2.2 | 0.82-1.0 | Professional/competitive level |
| Older Adults (60+) | 1.0-1.3 | 0.45-0.6 | Combat sarcopenia |
Key Research Findings:
-
The 1.6g/kg threshold: A 2018 meta-analysis by Morton et al. analyzing 49 studies found that protein intakes above 1.6g/kg had diminishing returns for muscle building in trained individuals. However, going up to 2.2g/kg caused no harm.
-
Higher during fat loss: A 2016 study found athletes eating 2.4g/kg during a deficit retained significantly more muscle than those eating 1.2g/kg—while both groups lost similar amounts of weight.
-
The RDA is a floor, not a ceiling: The 0.8g/kg RDA was designed to prevent protein deficiency in 97.5% of the population—it's not optimal for active individuals or older adults.
-
Quality matters: Animal proteins and soy are "complete" (contain all essential amino acids). Other plant proteins should be combined throughout the day for complete profiles.
Protein Distribution and Meal Timing
Research shows that HOW you distribute protein throughout the day matters almost as much as total intake for muscle building.
The Muscle Protein Synthesis (MPS) Threshold:
To maximally stimulate muscle protein synthesis, each meal should contain at least 20-40 grams of high-quality protein. Below this threshold, MPS isn't fully activated. Above ~40g, you get diminishing returns.
| Meal Size | MPS Response | Practical Application |
|---|---|---|
| <20g protein | Suboptimal | Combine with another protein source |
| 20-30g | Good | Minimum effective dose for most people |
| 30-40g | Optimal | Sweet spot for maximizing MPS |
| >40g | Diminishing returns | Extra used for energy, not more muscle |
Optimal Distribution Strategy:
| Meals/Day | Protein Per Meal | Best For |
|---|---|---|
| 3 meals | 30-50g each | General population, convenience |
| 4 meals | 25-40g each | Better MPS stimulation |
| 5-6 meals | 20-35g each | Serious athletes, very high protein needs |
The Post-Workout "Window":
The anabolic window is real but not as narrow as gym bros claim:
- Optimal: Consume 20-40g protein within 2 hours of training
- Still beneficial: Up to 4-6 hours post-workout
- Myth: You don't need to chug a shake within 30 minutes
Pre-Sleep Protein Benefits:
Research shows 30-40g of casein (or cottage cheese/Greek yogurt) before bed:
- Increases overnight muscle protein synthesis by 22%
- Improves next-morning recovery markers
- Does NOT interfere with sleep quality
- May actually improve sleep in some studies
Breakfast Protein Importance:
Starting your day with 30g+ protein:
- Breaks the overnight catabolic state
- Reduces hunger and cravings all day
- Stabilizes blood sugar and energy levels
- Sets up better food choices throughout the day
Complete vs Incomplete Proteins Explained
Proteins are made of amino acids. Your body needs all 20, and 9 of them are "essential"—meaning you must get them from food.
Complete Proteins (all 9 essential amino acids in adequate amounts):
- All animal proteins: meat, poultry, fish, eggs, dairy
- Soy products: tofu, tempeh, edamame, soy milk
- A few plant sources: quinoa, buckwheat, hemp seeds
Incomplete Proteins (low in one or more essential amino acids):
- Most legumes: beans, lentils, peas (low in methionine)
- Grains and cereals: rice, bread, pasta (low in lysine)
- Most nuts and seeds: almonds, peanuts (variable profiles)
The Combining Myth—Partially Debunked:
Old advice said you must combine proteins at every meal. Modern research shows you just need variety throughout the day. Your body pools amino acids and uses them as needed.
| Classic Combination | Why It Works |
|---|---|
| Rice + Beans | Grains provide methionine; beans provide lysine |
| Hummus + Pita | Chickpeas + wheat = complete |
| Peanut butter sandwich | Peanuts + bread = complete |
| Lentil soup + bread | Lentils + grains = complete |
Protein Quality Scores (PDCAAS):
| Protein Source | Score | Digestibility | Best Use |
|---|---|---|---|
| Whey protein | 1.00 | 95% | Post-workout, convenience |
| Egg | 1.00 | 97% | Any meal, versatile |
| Casein | 1.00 | 92% | Before bed, slow release |
| Beef | 0.92 | 94% | Main meals, iron-rich |
| Soy | 0.91 | 95% | Plant-based alternative |
| Chicken | 0.95 | 95% | Main meals, lean |
| Black beans | 0.75 | 83% | Combine with grains |
| Wheat | 0.42 | 91% | Combine with legumes |
Leucine: The Key Amino Acid:
Leucine is the primary trigger for muscle protein synthesis. Animal proteins are leucine-rich; plant proteins are lower. For muscle building, aim for 2-3g leucine per meal.
| Food | Leucine per 30g protein |
|---|---|
| Whey | 3.0g |
| Beef | 2.4g |
| Chicken | 2.3g |
| Egg | 2.5g |
| Soy | 2.0g |
| Pea protein | 2.1g |
| Rice protein | 1.8g |
Protein for Fat Loss: Your Most Important Tool
High protein intake is arguably MORE important during weight loss than during muscle building. Here's the science:
Problem: You Lose Muscle During Fat Loss
When you eat in a caloric deficit, your body breaks down both fat AND muscle for energy. Without adequate protein, you can lose significant muscle mass—ending up "skinny fat" despite reaching your goal weight.
| Protein Intake | Muscle Loss During Cut | Body Composition Result |
|---|---|---|
| Low (0.8g/kg) | Significant (25%+ of loss) | Skinny fat |
| Moderate (1.2g/kg) | Moderate (15-20% of loss) | Better |
| High (2.0-2.5g/kg) | Minimal (<10% of loss) | Lean and defined |
The Thermic Effect Advantage:
Protein has a much higher thermic effect than carbs or fat—meaning you burn more calories just digesting it:
| Macronutrient | Thermic Effect | Net Calories from 200 cal |
|---|---|---|
| Protein | 20-30% | 140-160 calories |
| Carbohydrates | 5-10% | 180-190 calories |
| Fat | 0-3% | 194-200 calories |
This means high-protein diets effectively have a higher TDEE—you can eat more while losing the same amount.
Satiety: Protein Kills Hunger
Protein is the most satiating macronutrient:
- Reduces hunger hormone (ghrelin)
- Increases satiety hormones (GLP-1, PYY, CCK)
- Reduces late-night cravings and snacking
- Studies show high-protein dieters spontaneously eat 400-500 fewer calories per day
The Optimal Fat Loss Protocol:
| Factor | Recommendation | Why |
|---|---|---|
| Protein | 2.0-2.5g/kg | Preserve muscle, stay full |
| Deficit | 300-500 calories | Sustainable, minimizes muscle loss |
| Resistance training | 3-4x/week | Signal body to keep muscle |
| Cardio | Moderate | Support deficit, don't overdo |
| Sleep | 7-9 hours | Hormone optimization |
Real-World Example (180 lb person cutting):
- Protein: 180-200g/day
- Calories: TDEE minus 400 = ~2,100 cal
- Protein provides 720-800 calories (34-38%)
- Remaining calories split between carbs/fat based on preference
Plant-Based Protein: Meeting Needs Without Meat
Meeting protein needs on a vegetarian or vegan diet is entirely possible but requires more planning and volume.
Top Plant Protein Sources:
| Food | Protein/100g | Protein/Cup | Complete? | Notes |
|---|---|---|---|---|
| Seitan | 25g | 75g | No | Wheat gluten, meaty texture |
| Tempeh | 19g | 31g | Yes | Fermented soy, probiotic |
| Tofu (firm) | 17g | 40g | Yes | Versatile, absorbs flavors |
| Lentils (cooked) | 9g | 18g | No | High fiber, combine w/ grains |
| Chickpeas | 9g | 15g | No | Hummus, roasted, curries |
| Black beans | 9g | 15g | No | Classic with rice |
| Edamame | 11g | 17g | Yes | Easy snack, sushi addition |
| Quinoa | 4g | 8g | Yes | Grain substitute |
| Hemp seeds | 31g | 10g/3tbsp | Yes | Easy to sprinkle on anything |
| Nutritional yeast | 50g | N/A | Yes | Cheesy flavor, B12 fortified |
Vegan Protein Powders Compared:
| Type | Protein/Scoop | Taste | Amino Profile | Best For |
|---|---|---|---|---|
| Pea protein | 20-25g | Earthy | High leucine | Most versatile |
| Rice protein | 20-25g | Mild | Low lysine | Blend with pea |
| Pea + Rice blend | 20-25g | Best | Complete | Optimal choice |
| Soy isolate | 23-27g | Neutral | Complete | Muscle building |
| Hemp | 12-15g | Nutty | Complete | Lower protein, whole food |
Key Considerations for Plant-Based Athletes:
-
Eat 10-20% more protein: Plant proteins are ~85-90% digestible vs 95% for animal proteins
-
Prioritize leucine-rich sources: Soy, pea protein, and hemp have the most leucine among plant sources
-
Combine proteins throughout the day: Beans + grains, nuts + legumes for complete profiles
-
Consider supplements: Creatine (5g/day), B12 (essential), omega-3s (algae-based), vitamin D
-
Volume matters: You'll eat more food volume to hit protein targets—plan for larger meals
Sample High-Protein Vegan Day (180g target):
- Breakfast: Tofu scramble (25g) + protein smoothie (25g) = 50g
- Lunch: Tempeh stir-fry with quinoa (35g) = 35g
- Snack: Edamame + protein bar (25g) = 25g
- Dinner: Lentil curry with seitan (40g) = 40g
- Before bed: Soy protein shake (30g) = 30g
- Total: 180g
Protein for Older Adults (50+)
Protein becomes MORE important as you age, not less. Here's why and how to adjust:
The Problem: Sarcopenia (Age-Related Muscle Loss)
Starting around age 30, you lose 3-5% of muscle mass per decade. After 50, this accelerates. By 80, many people have lost 30-50% of their muscle mass. This affects:
- Strength and mobility
- Balance and fall risk
- Metabolic rate
- Independence and quality of life
The Solution: Higher Protein + Resistance Training
| Age Group | Minimum Protein | Optimal Protein |
|---|---|---|
| 18-50 | 0.8g/kg | 1.2-1.6g/kg |
| 50-65 | 1.0g/kg | 1.2-1.5g/kg |
| 65+ | 1.0-1.2g/kg | 1.2-1.5g/kg |
| 65+ (frail/recovering) | 1.2g/kg | 1.5-2.0g/kg |
Why Older Adults Need More Protein:
-
Anabolic resistance: Aging muscles respond less efficiently to protein. You need more to trigger the same muscle-building response.
-
Reduced appetite: Many older adults naturally eat less, making protein density more important.
-
Absorption changes: Digestive efficiency decreases with age.
-
Increased breakdown: Inflammatory conditions and illness increase protein breakdown.
Practical Tips for Older Adults:
| Strategy | Implementation |
|---|---|
| Protein at every meal | Minimum 25-30g per meal (vs 20g for younger adults) |
| Prioritize leucine | Dairy, eggs, and meat are leucine-rich |
| Easy-to-eat options | Greek yogurt, smoothies, eggs—don't require much chewing |
| Supplement if needed | Whey or casein are excellent for older adults |
| Combine with exercise | Resistance training is essential, even light weights help |
The Research is Clear:
A 2016 study found that older adults eating 1.6g/kg maintained significantly more muscle mass over 6 months than those eating 0.8g/kg—even without exercise. With resistance training, the benefits were even greater.
Key Message: The RDA of 0.8g/kg is insufficient for older adults. Aim for at least 1.2g/kg, distributed across 3-4 meals with at least 25-30g each.
High-Protein Foods: Quick Reference
Use this reference to hit your protein targets with real food:
Animal Proteins (per serving):
| Food | Serving Size | Protein | Calories | Protein/Calorie |
|---|---|---|---|---|
| Chicken breast | 4 oz | 31g | 165 | 0.19 |
| Ground turkey (93%) | 4 oz | 24g | 170 | 0.14 |
| Beef sirloin | 4 oz | 26g | 200 | 0.13 |
| Salmon | 4 oz | 25g | 235 | 0.11 |
| Tuna (canned) | 4 oz | 26g | 120 | 0.22 |
| Shrimp | 4 oz | 24g | 99 | 0.24 |
| Eggs (2 large) | 100g | 12g | 140 | 0.09 |
| Egg whites (4) | 130g | 14g | 68 | 0.21 |
| Greek yogurt (0%) | 1 cup | 17g | 100 | 0.17 |
| Cottage cheese (1%) | 1 cup | 28g | 160 | 0.18 |
Plant Proteins (per serving):
| Food | Serving Size | Protein | Calories | Protein/Calorie |
|---|---|---|---|---|
| Tofu (firm) | 1/2 block | 20g | 180 | 0.11 |
| Tempeh | 4 oz | 21g | 220 | 0.10 |
| Lentils (cooked) | 1 cup | 18g | 230 | 0.08 |
| Black beans | 1 cup | 15g | 230 | 0.07 |
| Edamame | 1 cup | 17g | 190 | 0.09 |
| Seitan | 3 oz | 21g | 120 | 0.18 |
Protein Supplements:
| Type | Serving | Protein | Best Timing |
|---|---|---|---|
| Whey concentrate | 1 scoop | 20-24g | Post-workout |
| Whey isolate | 1 scoop | 25-27g | Anytime, lower lactose |
| Casein | 1 scoop | 24g | Before bed |
| Pea protein | 1 scoop | 20-25g | Anytime (vegan) |
| Collagen | 1 scoop | 10g | Joints, not muscle building |
High-Protein Snacks:
| Snack | Protein | Good For |
|---|---|---|
| Greek yogurt cup | 15-17g | Creamy, filling |
| String cheese (2) | 14g | Portable |
| Beef jerky (2 oz) | 18g | Portable, shelf-stable |
| Hard-boiled eggs (2) | 12g | Meal prep friendly |
| Protein bar | 20g | Convenient, varies by brand |
| Cottage cheese | 14g per 1/2 cup | Pre-bed, versatile |
| Deli turkey (3 oz) | 15g | Quick, low-calorie |
Pro Tips
- 💡Front-load protein early in the day—a 30g+ protein breakfast reduces hunger, cravings, and total calorie intake throughout the day.
- 💡Keep high-protein snacks accessible: Greek yogurt, string cheese, beef jerky, hard-boiled eggs, protein bars, and edamame make hitting targets easy.
- 💡Add protein to every single meal: eggs at breakfast, chicken on salads, Greek yogurt in smoothies, cottage cheese with fruit, meat at dinner.
- 💡If you struggle with appetite, liquid protein (shakes, milk, smoothies) is easier to consume than whole food and counts equally toward your target.
- 💡Batch cook protein sources weekly: grill chicken breasts, hard-boil eggs, prepare lentils and beans. Ready-to-eat protein eliminates excuses.
- 💡Read nutrition labels carefully—many "protein" products are mostly carbs. Compare grams of protein per 100 calories, not just per serving.
- 💡During fat loss, protect your muscle by eating 2.0-2.5g/kg protein. This is MORE important during cutting than during bulking.
- 💡Combine plant proteins throughout the day for complete amino acid profiles: rice + beans, hummus + pita, lentils + grains.
- 💡Consider casein protein or Greek yogurt before bed—research shows it increases overnight muscle protein synthesis by 22%.
- 💡Older adults (65+) should aim for at least 25-30g protein per meal to overcome age-related anabolic resistance.
- 💡If hitting protein targets through food is difficult, one or two protein shakes daily is a simple solution—but prioritize whole foods when possible.
- 💡Track your protein for at least two weeks to understand your baseline. Most people dramatically overestimate their intake.
Frequently Asked Questions
Research supports 1.6-2.2 grams of protein per kilogram of body weight (0.73-1.0g per pound) for muscle building. For a 180 lb person, that's 130-180g daily. The 2018 meta-analysis by Morton et al. found diminishing returns above 1.6g/kg, but going up to 2.2g/kg is safe and may benefit some individuals, especially during fat loss phases or intense training periods.
