How much protein do I need per day?

The minimum Recommended Dietary Allowance (RDA) for protein is 0.8 grams per kilogram of body weight per day for sedentary adults, which translates to about 56 g for a 70 kg person. However, research consistently shows that higher intakes provide greater benefits for active individuals. Moderately active people benefit from 1.2 g/kg, regular exercisers from 1.6 g/kg, and athletes from 2.0-2.2 g/kg. For a 75 kg person who exercises regularly, that means 120-165 g of protein per day. The International Society of Sports Nutrition recommends 1.4-2.0 g/kg for people engaged in regular exercise.

When is the best time to eat protein for muscle building?

Distributing protein evenly across 3-4 meals throughout the day (every 3-5 hours) is more effective for muscle protein synthesis than consuming it all in one sitting. Each meal should contain 20-40 g of protein to maximally stimulate MPS. Consuming protein within 2 hours after resistance training supports recovery, though the "anabolic window" is broader than previously thought. A meta-analysis published in the Journal of the International Society of Sports Nutrition found that total daily protein intake matters more than precise timing. A pre-bed serving of 30-40 g of slow-digesting casein protein has been shown to enhance overnight muscle recovery.

Can I get enough protein from plant-based sources?

Yes, you can meet all protein needs with plant-based sources, though it requires more planning. Good options include lentils (18 g per cup), tofu (17 g per 100 g), tempeh (19 g per 100 g), chickpeas (15 g per cup), quinoa (8 g per cup), and edamame (17 g per cup). Since most plant proteins are incomplete (missing one or more essential amino acids), combine different sources throughout the day -- for example, rice with beans or hummus with whole wheat bread. Soy, quinoa, and buckwheat are complete plant proteins. Plant-based athletes may benefit from aiming 10-15% higher than animal-based protein recommendations to account for slightly lower digestibility, per a 2019 review in Nutrients.

Is too much protein harmful to kidneys?

For healthy individuals with normal kidney function, consuming up to 2.2 g/kg of body weight per day has not been shown to cause kidney damage in multiple long-term studies. A systematic review published in the Journal of Nutrition found no evidence that high protein intake harms healthy kidneys. However, people with existing chronic kidney disease (CKD) should follow their doctor's protein recommendations, which are typically 0.6-0.8 g/kg. High protein intake does increase the kidneys' workload, so staying well hydrated is important. If you have concerns about kidney health, consult a nephrologist before significantly increasing protein intake.

Do older adults need more protein?

Yes, research suggests that adults over 65 need more protein to maintain muscle mass and prevent sarcopenia (age-related muscle loss). The PROT-AGE Study Group recommends 1.0-1.2 g/kg per day for healthy older adults, increasing to 1.2-1.5 g/kg for those with acute or chronic illness. Sarcopenia affects approximately 10% of adults over 60 and up to 50% of those over 80, per research in Age and Ageing. Higher protein intake combined with resistance training is the most effective strategy to slow muscle loss. Older adults also benefit from higher per-meal doses (25-40 g) because the muscle protein synthesis response becomes less sensitive with age, requiring a larger stimulus.

Does protein help with weight loss?

Protein supports weight loss through multiple mechanisms. First, it is the most satiating macronutrient, helping you feel fuller longer and reducing overall calorie intake. Second, protein has the highest thermic effect of food at 20-30%, meaning your body burns more calories digesting protein than carbs or fat. Third, adequate protein (1.6-2.4 g/kg) during a caloric deficit preserves lean muscle mass, ensuring that weight loss comes primarily from fat rather than muscle. A study in the American Journal of Clinical Nutrition found that participants on a high-protein diet (2.4 g/kg) in a caloric deficit gained lean mass while losing fat, compared to a lower-protein group that lost both muscle and fat.

Protein Calculator

Quick Answer

The Recommended Dietary Allowance (RDA) for protein from the US Institute of Medicine is 0.8 grams per kilogram of body weight per day for sedentary adults. Athletes and active adults typically need 1.2-2.0 g/kg; strength-training adults targeting muscle gain often use 1.6-2.2 g/kg.

Also searched as: protein calculator, daily protein calculator, protein intake calculator

Weight Unit

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Daily Protein Intake

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Protein per Meal (3 meals)

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Protein per Meal (4 meals)

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Food Equivalents (approx daily)

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How the Protein Calculator Works

Protein is an essential macronutrient made up of amino acids that your body uses to build and repair muscle tissue, produce enzymes and hormones, support immune function, and maintain healthy skin, hair, and nails. This calculator estimates your optimal daily protein intake based on your body weight, physical activity level, and fitness goals using evidence-based multipliers endorsed by major nutrition organizations.

The National Academy of Medicine (formerly the Institute of Medicine) sets the Recommended Dietary Allowance (RDA) for protein at 0.8 g/kg of body weight per day for sedentary adults. However, research published in the Journal of the International Society of Sports Nutrition recommends significantly higher intakes of 1.6-2.2 g/kg for individuals engaged in regular exercise, particularly resistance training. The 0.8 g/kg RDA represents the minimum to prevent deficiency, not the optimal amount for health and performance.

The results break down your daily target into per-meal amounts for 3 or 4 meals, since distributing protein evenly throughout the day optimizes muscle protein synthesis. You can also use our Macro Calculator to see how protein fits into your total calorie budget, and our Calorie Calculator to determine your overall energy needs.

The Protein Intake Formula

Daily Protein Requirement:

Daily Protein (g) = Body Weight (kg) × Protein Multiplier (g/kg)

The protein multiplier varies by activity level and goal:

Sedentary: 0.8 g/kg (RDA minimum)
Moderately active: 1.2 g/kg
Active (regular exercise): 1.6 g/kg
Athlete/intense training: 2.0 g/kg
Muscle building goal: Add 0.2 g/kg to your base multiplier

Worked example: A 75 kg active person aiming to build muscle. Base multiplier = 1.6 g/kg + 0.2 g/kg muscle building bonus = 1.8 g/kg. Daily protein = 75 × 1.8 = 135 g/day, or approximately 45 g per meal across 3 meals. This equals about 540 calories from protein (135 g × 4 cal/g).

Key Terms You Should Know

Complete Protein contains all nine essential amino acids in sufficient quantities. Animal sources (meat, fish, eggs, dairy) are complete proteins. Most plant sources are incomplete, though soy, quinoa, and buckwheat are exceptions.

Muscle Protein Synthesis (MPS) is the biological process where amino acids from dietary protein are incorporated into skeletal muscle tissue. MPS is maximally stimulated by consuming 20-40 g of high-quality protein per meal, with diminishing returns above this range.

Leucine is a branched-chain amino acid (BCAA) that serves as the primary trigger for muscle protein synthesis. A threshold of approximately 2-3 g of leucine per meal is needed to maximally stimulate MPS. Whey protein, eggs, and chicken are particularly leucine-rich.

Biological Value (BV) measures how efficiently your body utilizes protein from a particular food source. Eggs have a BV of 100 (reference standard), whey protein scores 104, beef scores 80, and beans score approximately 49.

Thermic Effect of Food (TEF) refers to the calories burned during digestion. Protein has the highest TEF of any macronutrient at 20-30%, meaning your body uses 20-30% of protein calories just to digest and absorb it, compared to 5-10% for carbs and 0-3% for fat.

Protein Content of Common Foods

The following table shows protein content per standard serving, sourced from the USDA FoodData Central database:

Food	Serving Size	Protein (g)	Calories
Chicken breast (cooked)	100 g / 3.5 oz	31 g	165
Eggs (large)	2 eggs	12 g	144
Greek yogurt (plain, nonfat)	170 g / 6 oz	17 g	100
Salmon (cooked)	100 g / 3.5 oz	25 g	208
Lentils (cooked)	1 cup / 200 g	18 g	230
Tofu (firm)	100 g / 3.5 oz	17 g	144
Whey protein powder	1 scoop (30 g)	24 g	120
Cottage cheese (low-fat)	1 cup / 226 g	28 g	183

Practical Examples

Example 1 -- Sedentary adult maintaining health: A 60 kg woman with a desk job. Protein = 60 × 0.8 = 48 g/day. This is about 16 g per meal across 3 meals -- easily achievable with a chicken breast at lunch (31 g) and a cup of lentils at dinner (18 g).

Example 2 -- Active gym-goer cutting weight: An 85 kg man who lifts weights 4 days per week and wants to lose fat while preserving muscle. Protein = 85 × 1.6 = 136 g/day. During a caloric deficit, research from a 2016 study in the American Journal of Clinical Nutrition found that consuming 2.4 g/kg during a cut preserved significantly more lean mass than 1.2 g/kg. He might aim for 170 g (2.0 g/kg) distributed as 42 g across 4 meals.

Example 3 -- Vegan athlete: A 70 kg woman training for a triathlon. Protein = 70 × 2.0 = 140 g/day. Plant proteins are slightly less bioavailable, so she may aim for 10-15% more (154 g). A sample day: tofu scramble (34 g), lentil soup with quinoa (28 g), tempeh stir-fry with edamame (35 g), protein shake with pea protein (24 g), plus snacks like nuts and hummus for the remaining 33 g. Use our TDEE Calculator to ensure total calories support her training volume.

Tips for Meeting Your Protein Target

Distribute protein evenly across meals. Research shows that consuming 20-40 g of protein per meal (every 3-5 hours) maximizes muscle protein synthesis throughout the day. Front-loading all protein at dinner is less effective than spreading it out.
Prioritize protein at breakfast. Most people eat protein-heavy dinners but protein-light breakfasts. Adding eggs, Greek yogurt, cottage cheese, or a protein shake to your morning routine helps you hit daily targets more easily.
Choose high-protein snacks. Replace chips and crackers with Greek yogurt, beef jerky, edamame, cottage cheese, or protein bars. These options contribute 15-25 g per snack without excessive calories.
Use protein supplements strategically. Whey protein (fast-absorbing) is ideal post-workout, while casein (slow-absorbing) is useful before bed. Plant-based options like pea and rice protein blends provide comparable muscle-building benefits when combined.
Increase protein during caloric deficits. When cutting calories, increase protein to 1.8-2.4 g/kg to preserve lean muscle mass. Higher protein also increases satiety, reducing hunger during dieting.
Track for two weeks to build awareness. Use a food diary or tracking app to learn which of your regular foods are protein-rich and where gaps exist. After two weeks, most people develop an intuitive sense of their intake.

Disclaimer: This calculator provides estimates for informational purposes only and does not constitute medical or dietary advice. Consult a healthcare professional before making significant changes to your diet, especially if you have kidney disease or other conditions that may require protein restriction.