Protein Calculator

Find out exactly how much protein your body needs every day based on your weight, activity level, and fitness goal.

Protein Calculator

Calculate your daily protein needs

Protein Calculator

Based on weight and activity level

Formula
Protein (g) = Weight (lbs) x Activity Factor

What Is Protein and Why Does It Matter?

Protein is one of three essential macronutrients your body can't function without. It's built from amino acids — the molecular building blocks your cells use to repair muscle tissue, synthesize enzymes, produce hormones, and keep your immune system running. Unlike carbohydrates or fat, your body doesn't store a large reservoir of protein, which means you need a steady daily supply from food to meet ongoing demand.

How much protein you actually need depends on more than just your body weight. A desk worker maintaining their current weight has very different requirements from a competitive cyclist or someone trying to add lean muscle mass. Research consistently shows that higher protein intakes support fat loss by increasing satiety, preserve lean body mass during caloric restriction, and accelerate recovery after strength or endurance training. Getting the number right — not just 'eating enough chicken' — makes a real, measurable difference in outcomes.

How to Use This Calculator

  1. 1Enter your body weight in kilograms or pounds — use your current weight, not a goal weight.
  2. 2Select your activity level: sedentary (desk job, little exercise), lightly active, moderately active, very active, or athlete.
  3. 3Choose your primary goal: maintain weight, lose weight, build muscle, or maximize athletic performance.
  4. 4Click Calculate to see your recommended daily protein intake in grams, along with the caloric contribution from protein.

Protein Formulas and Reference Values

Protein recommendations (per kg of bodyweight): Sedentary adult (RDA): 0.8 g/kg Lightly active / weight loss: 1.2–1.6 g/kg Endurance athlete: 1.4–1.7 g/kg Strength training / muscle gain: 1.6–2.2 g/kg High-intensity athlete: 2.0–3.1 g/kg Per pound: multiply kg recommendation by 0.454 Example: 2.2 g/kg × 0.454 = 1.0 g/lb

Reference values are drawn from the ISSN (International Society of Sports Nutrition) position stand on protein and exercise. Use the higher end of the range if you are in a caloric deficit, a beginner to training, or over 50 years old — all three situations increase the minimum effective dose.

Worked Examples

70 kg sedentary office worker

Applying the RDA baseline: 0.8 g/kg × 70 kg = 56 g of protein per day. This covers basic bodily maintenance — enzyme production, immune function, and tissue turnover — but provides little margin for exercise recovery or muscle retention during aging.

80 kg recreational gym-goer (muscle gain goal)

At a moderate muscle-building target of 2.0 g/kg: 2.0 × 80 kg = 160 g of protein per day. Since protein provides 4 calories per gram, that's 640 calories from protein alone — roughly 25–30% of a typical 2,200–2,500 calorie bulking diet. Spreading this across 4–5 meals maximizes muscle protein synthesis.

60 kg female endurance runner

Using the mid-range endurance recommendation of 1.6 g/kg: 1.6 × 60 kg = 96 g of protein per day. Endurance athletes often underestimate their protein needs because they focus on carbohydrate loading, but muscle repair after long runs demands meaningful amino acid availability throughout the day.

Frequently Asked Questions

Can you eat too much protein?▾
For healthy adults, high protein intakes — even above 3 g/kg/day — have not been shown to damage kidneys or liver in multiple controlled studies. The main practical downside is caloric: protein isn't calorie-free, and eating far above your needs can displace carbohydrates or fats you actually need for performance. If you have pre-existing kidney disease, consult a physician before significantly increasing protein intake.
What are complete vs. incomplete protein sources?▾
A complete protein contains all nine essential amino acids your body cannot produce on its own. Animal sources — chicken, beef, eggs, dairy, fish — are all complete. Most plant sources are incomplete (lacking one or more essential amino acids), but you don't need to combine them in a single meal. Eating a variety of legumes, grains, nuts, and seeds across the day provides your full amino acid profile. Soy, quinoa, and hemp seed are notable complete plant proteins.
Does protein timing matter?▾
Protein timing has a smaller effect than total daily intake, but it's not irrelevant. Distributing protein across 3–5 meals (roughly 20–40 g per meal) maximizes muscle protein synthesis better than concentrating most of it in one sitting. Consuming 20–40 g of protein within 1–2 hours after a workout supports recovery, though the 'anabolic window' is wider than once thought — total daily protein is the bigger lever.
Is plant protein as effective as animal protein for muscle growth?▾
Gram-for-gram, animal protein has a slight edge due to higher leucine content and better digestibility. However, multiple studies show that when total protein intake is matched and plant sources are varied (so all essential amino acids are covered), muscle growth and strength gains are equivalent. Plant-based athletes may benefit from targeting the higher end of the protein range (2.0–2.2 g/kg) to account for slightly lower absorption.
What happens to excess protein in the body?▾
Protein your body can't use for tissue repair or synthesis is broken down by the liver. The nitrogen portion is excreted as urea in urine, while the carbon skeleton is either used for energy immediately or converted to glucose (gluconeogenesis) or, in large surpluses, stored as fat. This conversion process is metabolically costly, which is why protein has a higher thermic effect of food than carbohydrates or fat — your body burns more calories just processing it.