Calculate your optimal protein needs based on your body weight, activity level, and fitness goals.
Kilograms (kg)
Pounds (lb)
Sedentary (Little/no exercise)
Moderate (Exercise 3-4 times/week)
Very Active (Daily intense training)
Elite Athlete/Bodybuilder
Maintenance
Muscle Gain / Bulking
Fat Loss / Cutting
Your Recommended Daily Protein:
0g – 0g
*Based on clinical guidelines for optimal nitrogen balance and muscle protein synthesis.
Understanding Protein Requirements in Food
Protein is the building block of life, essential for repairing tissues, producing enzymes, and supporting muscle growth. Determining how much protein you need depends heavily on your lifestyle and body composition.
How the Calculator Works
This protein calculator uses scientifically backed ratios to estimate your needs. For a standard sedentary adult, the Recommended Dietary Allowance (RDA) is 0.8 grams per kilogram of body weight. However, for those looking to lose fat without losing muscle, or those looking to build strength, that number increases significantly.
Protein Content in Common Foods
Knowing your target is only half the battle; the next step is knowing what to eat. Here is a quick reference for protein in common food items per 100 grams:
Food Item (100g)
Protein Content (g)
Chicken Breast (Cooked)
31g
Canned Tuna (Drained)
26g
Lentils (Cooked)
9g
Greek Yogurt (Plain)
10g
Eggs (approx. 2 large)
13g
Tofu (Firm)
8g
Examples of Daily Protein Math
If you are a 180lb (81kg) male looking to build muscle, the calculation might look like this:
Weight: 81kg
Activity Factor: 2.0g per kg
Total: 162 grams of protein per day
To reach this goal, you would need to consume roughly 5 portions of food containing 32g of protein each (e.g., a chicken breast, a protein shake, a cup of Greek yogurt, etc.).
function calculateProtein() {
var weight = parseFloat(document.getElementById('p-weight').value);
var unit = document.getElementById('p-unit').value;
var activity = document.getElementById('p-activity').value;
var goal = document.getElementById('p-goal').value;
var resultBox = document.getElementById('protein-result-box');
var output = document.getElementById('protein-output');
var description = document.getElementById('protein-description');
if (isNaN(weight) || weight <= 0) {
alert("Please enter a valid weight.");
return;
}
// Convert everything to KG for standard calculation
var weightInKg = weight;
if (unit === 'lb') {
weightInKg = weight / 2.20462;
}
var minRatio, maxRatio;
// Logic based on activity and goal
if (activity === 'sedentary') {
minRatio = 0.8;
maxRatio = 1.0;
} else if (activity === 'moderate') {
minRatio = 1.2;
maxRatio = 1.5;
} else if (activity === 'active') {
minRatio = 1.6;
maxRatio = 2.0;
} else { // athlete
minRatio = 2.0;
maxRatio = 2.4;
}
// Adjustments for Goals
if (goal === 'muscle') {
minRatio += 0.2;
maxRatio += 0.2;
} else if (goal === 'fatloss') {
// Higher protein is often recommended during calorie deficits to preserve lean mass
minRatio += 0.3;
maxRatio += 0.4;
}
var dailyMin = Math.round(weightInKg * minRatio);
var dailyMax = Math.round(weightInKg * maxRatio);
output.innerHTML = dailyMin + "g – " + dailyMax + "g";
var descText = "To meet your " + goal + " goals with your current activity level, aim for approximately " + dailyMin + " to " + dailyMax + " grams of protein spread across 3-5 meals per day.";
description.innerHTML = descText;
resultBox.style.display = 'block';
}