Introduction
Protein is one of the most important nutrients your body needs. It helps build and repair muscles, supports your immune system, and keeps you feeling full after meals. But how much protein should you actually eat each day? The answer depends on your age, weight, activity level, and fitness goals.
This Protein Calculator shows how much protein to eat each day. Simply enter your basic details, like your age, gender, height, and weight, then choose your activity level and fitness goal. The calculator gives you a personalized protein recommendation for your goal: losing fat, building muscle, maintaining your current weight, or boosting athletic performance. It also shows your estimated calorie needs, a suggested meal-by-meal protein breakdown, and a handy reference chart so you can compare intake levels across different goals. Use it to build a smarter eating plan that fits your body and your lifestyle.
How to Use Our Protein Calculator
Enter your body details and fitness goal below, and this calculator will tell you how many grams of protein you should eat each day, along with a meal-by-meal breakdown and calorie estimates.
Unit System: Choose between US Units (pounds and feet/inches), Metric Units (kilograms and centimeters), or Other Units if you need to convert from stones or meters. The calculator will automatically switch your inputs to match the system you pick.
Age: Enter your current age in years. This must be between 18 and 80. Your age helps the calculator figure out your basal metabolic rate (BMR), which affects your overall calorie and protein needs.
Gender: Select Male or Female. Men and women have different metabolic rates, so this choice helps the calculator give you a more accurate protein recommendation.
Height: Enter your height in feet and inches if using US Units, or in centimeters if using Metric Units. Your height is used alongside your weight and age to estimate how many calories your body burns at rest.
Weight: Enter your current body weight in pounds (US Units) or kilograms (Metric Units). Your weight is one of the most important inputs because your daily protein target is calculated as a certain number of grams per pound of body weight.
Activity Level: Pick the option that best describes how often and how hard you exercise each week. Choices range from Sedentary (little or no exercise) to Extra Active (very intense daily training or a physical job). A higher activity level means your body burns more calories and may need more protein.
BMR Formula: Choose Mifflin-St Jeor for most people. If you know your body fat percentage, you can switch to Katch-McArdle for a more precise estimate based on lean body mass.
Body Fat % (optional): This field only appears if you select the Katch-McArdle formula. Enter your body fat percentage so the calculator can estimate your lean mass. If you do not know this number, stick with the default Mifflin-St Jeor formula.
Fitness Goal: Select the goal that matches what you are working toward. Choose Weight Loss / Fat Loss to get a higher protein target that helps preserve muscle. Choose Maintenance / General Health for a balanced everyday intake. Choose Muscle Gain / Hypertrophy if you want to build muscle. Choose Endurance / Athletic Performance if you focus on long-distance or sustained activities.
Number of Meals Per Day: Use the slider to pick how many meals you eat each day, from 2 to 8. The calculator will split your total daily protein evenly across your meals and suggest timing for each one so you can space your protein intake throughout the day.
Once everything is filled in, click the Calculate Protein button to see your results. You will get your daily protein recommendation in grams, a suggested range, your estimated BMR and TDEE (total daily energy expenditure), calories from protein, protein per pound and per kilogram of body weight, a color-coded meal distribution bar, and a comparison chart showing protein needs across all four fitness goals. Click Reset at any time to return all inputs to their default values.
How Much Protein Do You Really Need?
Protein is one of the three macronutrients your body needs every day, along with carbohydrates and fat. It is made up of smaller building blocks called amino acids, which your body uses to build and repair muscles, make enzymes and hormones, support your immune system, and keep your skin, hair, and nails healthy. Unlike fat, your body cannot store extra protein for later use, so you need to eat enough of it each day.
Why Protein Intake Varies from Person to Person
There is no single number that works for everyone. How much protein you need depends on several things, including your body weight, age, gender, how active you are, and what your fitness goals are. A person trying to lose weight needs more protein per pound of body weight than someone just trying to stay healthy. This is because extra protein helps protect your muscles when you eat fewer calories. Someone trying to build muscle also needs more protein to fuel muscle growth and repair after workouts.
Protein Recommendations by Goal
This calculator uses the following ranges by goal. The International Society of Sports Nutrition's position stand puts daily intake for most exercising people at 1.4 to 2.0 g per kg of body weight and suggests 2.3 to 3.1 g per kg to hold on to lean mass while cutting calories.2
- Weight Loss / Fat Loss: 0.90–1.10 g per pound (2.0–2.4 g per kg). Higher protein helps you feel full longer and prevents muscle loss during a calorie deficit.
- Maintenance / General Health: 0.70–0.90 g per pound (1.6–2.0 g per kg). This range supports normal body functions and everyday activity.
- Muscle Gain / Hypertrophy: 0.90–1.20 g per pound (2.0–2.6 g per kg). Your muscles need extra amino acids to grow after strength training.
- Endurance / Athletic Performance: 0.70–1.00 g per pound (1.6–2.2 g per kg). Endurance athletes break down muscle during long training sessions and need protein for recovery.
How the Calculator Works
This calculator uses your weight, height, age, gender, and activity level to first estimate your Basal Metabolic Rate (BMR), the number of calories your body burns at rest. It supports two well-known BMR formulas. The Mifflin-St Jeor equation, published in 1990, is the default;4 a systematic review found it the most reliable of the common equations.6 The Katch-McArdle formula is an option if you know your body fat percentage, since it uses lean body mass (weight times one minus your body fat fraction); the equation, 370 + 21.6 × lean mass, is the general prediction equation Cunningham published in 1991.5 Your BMR is then multiplied by an activity factor to find your Total Daily Energy Expenditure (TDEE), which represents all the calories you burn in a day.
Based on your chosen fitness goal, the calculator applies the appropriate protein multiplier to your body weight and gives you a daily protein target in grams, a recommended range, and the percentage of your total calories that come from protein.
Spreading Protein Across Your Meals
How you divide your protein throughout the day matters. The International Society of Sports Nutrition reports that 20 to 40 grams of protein per meal, every three to four hours, most favorably affects muscle protein synthesis, while naming your total daily protein as the primary thing to get right.1 A 2018 review reached a similar conclusion, recommending about 0.4 g per kg per meal across at least four meals to reach 1.6 g per kg a day.3 The meal distribution feature in this calculator breaks your daily target into equal portions based on how many meals you eat, and suggests timing for each one.
Good Sources of Protein
To hit your daily target, focus on high-quality protein sources such as chicken breast, eggs, Greek yogurt, fish, lean beef, tofu, lentils, and cottage cheese. Meat, fish, eggs, dairy, legumes and soy foods all supply substantial protein per serving. Mixing animal and plant sources helps you get a complete range of amino acids.
Important Things to Keep in Mind
This calculator is designed for healthy adults ages 18–80. Pregnant or breastfeeding women, people with kidney disease, and children have different protein needs and should talk to a doctor or registered dietitian. Also, these numbers are estimates. Your actual needs may vary based on your metabolism, body composition, and training intensity. Use the results as a solid starting point, then adjust based on how your body responds over time.