Sedentary (Little to no exercise)
Lightly Active (Light exercise/sports 1-3 days/week)
Moderately Active (Moderate exercise/sports 3-5 days/week)
Very Active (Hard exercise/sports 6-7 days a week)
Extra Active (Very hard exercise/sports & physical job)
Weight Maintenance
Weight Loss
Weight Gain
Understanding Your Carbohydrate Intake
Carbohydrates are one of the three main macronutrients, providing the body with its primary source of energy. Understanding how to calculate your recommended daily carbohydrate intake is crucial for managing weight, optimizing athletic performance, and supporting overall health. This calculator helps you estimate your daily carbohydrate needs based on your activity level and dietary goals.
How the Calculation Works
The calculation involves estimating your Total Daily Energy Expenditure (TDEE) and then allocating a percentage of that to carbohydrates, depending on your goal.
1. Basal Metabolic Rate (BMR): This is the number of calories your body burns at rest. A common formula like the Mifflin-St Jeor equation is often used:
For men: BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5
For women: BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161
*(Note: This calculator simplifies this by directly asking for an estimated TDEE based on activity level, as age and sex are not included as inputs to keep the calculator focused on carbohydrates.)*
2. Total Daily Energy Expenditure (TDEE): This is your BMR multiplied by an activity factor:
Sedentary: BMR × 1.2
Lightly Active: BMR × 1.375
Moderately Active: BMR × 1.55
Very Active: BMR × 1.725
Extra Active: BMR × 1.9
*(This calculator uses predefined calorie targets adjusted for activity level, serving as a proxy for TDEE.)*
3. Carbohydrate Calculation: Once TDEE is estimated, the percentage allocated to carbohydrates varies:
Weight Maintenance: Typically 45-65% of total calories from carbohydrates. We'll use 50%.
Weight Loss: Often requires a moderate carbohydrate intake, around 40-50%. We'll use 45%.
Weight Gain: Usually requires a higher carbohydrate intake, around 50-60%. We'll use 55%.
Carbohydrates provide 4 calories per gram. Therefore:
Total Carbohydrates (grams) = (TDEE × Percentage for Carbs) / 4
The "Carbohydrates per Serving" and "Number of Servings" inputs allow you to see how your current food choices fit into your calculated needs. The final output shows your estimated daily carbohydrate target in grams.
Use Cases
Athletes and Fitness Enthusiasts: Optimizing carbohydrate intake for energy and recovery.
Individuals Managing Diabetes: Monitoring carbohydrate consumption for blood sugar control.
Weight Management: Adjusting carbohydrate intake as part of a balanced diet for weight loss or gain.
General Health and Nutrition: Ensuring adequate energy intake from a healthy macronutrient balance.
Disclaimer: This calculator provides an estimate for informational purposes only. Consult with a healthcare professional or registered dietitian for personalized dietary advice.
function calculateCarbohydrates() {
var gramsPerServing = parseFloat(document.getElementById("gramsPerServing").value);
var numberOfServings = parseFloat(document.getElementById("numberOfServings").value);
var activityLevel = document.getElementById("activityLevel").value;
var goal = document.getElementById("goal").value;
var resultDiv = document.getElementById("result");
resultDiv.innerHTML = ""; // Clear previous results
// Basic validation
if (isNaN(gramsPerServing) || gramsPerServing <= 0) {
resultDiv.innerHTML = "Please enter a valid number for carbohydrates per serving.";
return;
}
if (isNaN(numberOfServings) || numberOfServings <= 0) {
resultDiv.innerHTML = "Please enter a valid number for servings.";
return;
}
var caloriePerGramCarb = 4;
var estimatedTdee = 0;
var carbPercentage = 0;
// Estimate TDEE in calories (simplified: typical ranges for an average adult)
// These are rough estimates and vary greatly by individual factors like age, sex, weight, height.
if (activityLevel === "sedentary") {
estimatedTdee = 1800; // Example for sedentary
} else if (activityLevel === "lightly_active") {
estimatedTdee = 2200; // Example for lightly active
} else if (activityLevel === "moderately_active") {
estimatedTdee = 2600; // Example for moderately active
} else if (activityLevel === "very_active") {
estimatedTdee = 3000; // Example for very active
} else if (activityLevel === "extra_active") {
estimatedTdee = 3400; // Example for extra active
}
// Determine carbohydrate percentage based on goal
if (goal === "maintenance") {
carbPercentage = 0.50; // 50%
} else if (goal === "loss") {
carbPercentage = 0.45; // 45%
} else if (goal === "gain") {
carbPercentage = 0.55; // 55%
}
// Calculate target carbohydrate grams
var targetCarbGrams = (estimatedTdee * carbPercentage) / caloriePerGramCarb;
// Calculate current intake
var currentCarbIntake = gramsPerServing * numberOfServings;
// Display results
resultDiv.innerHTML =
"Your Estimated Daily Carbohydrate Target: " +
targetCarbGrams.toFixed(1) + " grams" +
"Your Current Intake from Servings: " + currentCarbIntake.toFixed(1) + " grams";
}