Keto Macro Calculator
Use this free keto calculator to determine your ideal daily macronutrient intake (carbohydrates, protein, and fat) for a ketogenic diet. Achieving the right macro balance is crucial for entering and maintaining ketosis, whether your goal is weight loss, maintenance, or muscle gain.
Understanding the Ketogenic Diet and Macro Calculation
The ketogenic diet is a very low-carb, high-fat diet that involves drastically reducing carbohydrate intake and replacing it with fat. This reduction in carbs puts your body into a metabolic state called ketosis. When this happens, your body becomes incredibly efficient at burning fat for energy. It also turns fat into ketones in the liver, which can supply energy for the brain.
Why Calculate Your Macros?
To successfully enter and maintain ketosis, it's essential to track your macronutrients (macros): carbohydrates, protein, and fat. Eating too many carbs will kick you out of ketosis, while insufficient fat can leave you hungry and lacking energy. Protein intake also needs to be optimized; too little can lead to muscle loss, and too much can be converted to glucose, hindering ketosis.
How This Calculator Works
Our Keto Macro Calculator uses your personal data to estimate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE). It then adjusts these figures based on your activity level and weight goal to provide a personalized macro breakdown.
- Basal Metabolic Rate (BMR): This is the number of calories your body burns at rest to maintain basic bodily functions. We use the Mifflin-St Jeor equation, which is widely considered one of the most accurate BMR formulas.
- Total Daily Energy Expenditure (TDEE): Your TDEE is your BMR multiplied by an activity factor, representing the total calories you burn in a day, including exercise and daily movement.
- Goal Adjustment: The calculator then adjusts your TDEE to create a calorie deficit (for weight loss) or surplus (for weight gain), or keeps it the same (for maintenance).
- Macronutrient Breakdown:
- Carbohydrates: Set to your desired net carb limit (typically 20-30g for strict keto).
- Protein: Calculated based on your Lean Body Mass (LBM) and a protein multiplier. This ensures you get enough protein to preserve muscle without overdoing it.
- Fat: The remaining calories are allocated to fat, which is your primary energy source on a ketogenic diet.
Tips for a Successful Keto Journey
- Track Your Food: Use a food tracking app to accurately log your daily intake and ensure you're hitting your macro targets.
- Prioritize Whole Foods: Focus on nutrient-dense, whole foods like fatty meats, fish, eggs, avocados, nuts, seeds, and low-carb vegetables.
- Stay Hydrated: Drink plenty of water, as the keto diet can lead to increased water and electrolyte loss.
- Listen to Your Body: Adjust your macros as needed based on how you feel, your energy levels, and your progress.
- Consult a Professional: If you have any underlying health conditions or concerns, consult with a doctor or registered dietitian before starting a ketogenic diet.
.keto-calculator-container {
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
max-width: 700px;
margin: 20px auto;
padding: 25px;
border: 1px solid #e0e0e0;
border-radius: 10px;
background-color: #ffffff;
box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
color: #333;
}
.keto-calculator-container h2 {
text-align: center;
color: #2c3e50;
margin-bottom: 25px;
font-size: 2em;
}
.keto-calculator-container h3 {
color: #34495e;
margin-top: 30px;
margin-bottom: 15px;
font-size: 1.5em;
}
.keto-calculator-container h4 {
color: #34495e;
margin-top: 20px;
margin-bottom: 10px;
font-size: 1.2em;
}
.keto-calculator-container p {
line-height: 1.6;
margin-bottom: 15px;
}
.calculator-form .form-group {
margin-bottom: 18px;
display: flex;
flex-wrap: wrap;
align-items: center;
}
.calculator-form label {
flex: 1 1 200px;
margin-right: 15px;
font-weight: 600;
color: #555;
}
.calculator-form input[type="number"],
.calculator-form select {
flex: 2 1 250px;
padding: 10px 12px;
border: 1px solid #ccc;
border-radius: 5px;
font-size: 1em;
box-sizing: border-box;
max-width: calc(100% – 220px); /* Adjust based on label width */
}
.calculator-form input[type="radio"] {
margin-right: 5px;
margin-left: 15px;
}
.calculator-form input[type="radio"] + label {
flex: 0 0 auto;
margin-right: 20px;
font-weight: normal;
}
.calculator-form small {
flex-basis: 100%;
margin-left: 215px; /* Align with input fields */
font-size: 0.85em;
color: #777;
margin-top: 5px;
}
.calculator-form button {
display: block;
width: 100%;
padding: 12px 20px;
background-color: #28a745; /* Green for keto */
color: white;
border: none;
border-radius: 5px;
font-size: 1.1em;
font-weight: bold;
cursor: pointer;
transition: background-color 0.3s ease;
margin-top: 25px;
}
.calculator-form button:hover {
background-color: #218838;
}
.calculator-result {
margin-top: 30px;
padding: 20px;
border: 1px solid #d4edda;
background-color: #e9f7ef;
border-radius: 8px;
color: #155724;
font-size: 1.1em;
line-height: 1.8;
}
.calculator-result h3 {
color: #155724;
margin-top: 0;
margin-bottom: 15px;
text-align: center;
}
.calculator-result p {
margin-bottom: 8px;
}
.calculator-result strong {
color: #0a3d15;
}
.calculator-result .macro-breakdown {
display: flex;
justify-content: space-around;
margin-top: 20px;
flex-wrap: wrap;
}
.calculator-result .macro-item {
text-align: center;
padding: 10px;
flex: 1;
min-width: 120px;
margin: 5px;
background-color: #d1ecf1; /* Light blue for macro items */
border-radius: 5px;
color: #0c5460;
}
.calculator-result .macro-item strong {
display: block;
font-size: 1.3em;
margin-bottom: 5px;
color: #0c5460;
}
.calculator-result .macro-item span {
font-size: 0.9em;
}
.calculator-article ul {
list-style-type: disc;
margin-left: 20px;
margin-bottom: 15px;
}
.calculator-article ul li {
margin-bottom: 8px;
line-height: 1.6;
}
@media (max-width: 600px) {
.calculator-form label {
flex-basis: 100%;
margin-bottom: 5px;
}
.calculator-form input[type="number"],
.calculator-form select {
max-width: 100%;
flex-basis: 100%;
}
.calculator-form small {
margin-left: 0;
}
.calculator-result .macro-breakdown {
flex-direction: column;
}
.calculator-result .macro-item {
margin-bottom: 10px;
}
}
function calculateKetoMacros() {
// Get input values
var age = parseFloat(document.getElementById("age").value);
var gender = document.querySelector('input[name="gender"]:checked').value;
var weightLbs = parseFloat(document.getElementById("weightLbs").value);
var heightFeet = parseFloat(document.getElementById("heightFeet").value);
var heightInches = parseFloat(document.getElementById("heightInches").value);
var activityLevelMultiplier = parseFloat(document.getElementById("activityLevel").value);
var bodyFatPercentage = parseFloat(document.getElementById("bodyFatPercentage").value);
var goal = document.getElementById("goal").value;
var carbLimit = parseFloat(document.getElementById("carbLimit").value);
var proteinMultiplier = parseFloat(document.getElementById("proteinMultiplier").value);
var resultDiv = document.getElementById("ketoResult");
resultDiv.innerHTML = ""; // Clear previous results
// Input validation
if (isNaN(age) || age <= 0 ||
isNaN(weightLbs) || weightLbs <= 0 ||
isNaN(heightFeet) || heightFeet < 0 ||
isNaN(heightInches) || heightInches 11 ||
isNaN(bodyFatPercentage) || bodyFatPercentage 60 ||
isNaN(carbLimit) || carbLimit <= 0 ||
isNaN(proteinMultiplier) || proteinMultiplier <= 0) {
resultDiv.innerHTML = "Please enter valid positive numbers for all fields.";
return;
}
// Convert weight to kg and height to cm for BMR calculation
var weightKg = weightLbs * 0.453592;
var heightCm = (heightFeet * 30.48) + (heightInches * 2.54);
// 1. Calculate Basal Metabolic Rate (BMR) – Mifflin-St Jeor Equation
var bmr;
if (gender === "male") {
bmr = (10 * weightKg) + (6.25 * heightCm) – (5 * age) + 5;
} else { // female
bmr = (10 * weightKg) + (6.25 * heightCm) – (5 * age) – 161;
}
// 2. Calculate Total Daily Energy Expenditure (TDEE)
var tdee = bmr * activityLevelMultiplier;
// 3. Adjust TDEE for Goal
var adjustedTDEE = tdee;
if (goal === "lose") {
adjustedTDEE = tdee * 0.80; // 20% calorie deficit
} else if (goal === "gain") {
adjustedTDEE = tdee * 1.15; // 15% calorie surplus
}
adjustedTDEE = Math.round(adjustedTDEE); // Round to nearest whole calorie
// 4. Calculate Macronutrients
// Carbs
var carbGrams = carbLimit;
var carbCalories = carbGrams * 4;
// Protein
var leanBodyMassLbs = weightLbs * (1 – (bodyFatPercentage / 100));
var proteinGrams = leanBodyMassLbs * proteinMultiplier;
var proteinCalories = proteinGrams * 4;
// Fat (remaining calories)
var fatCalories = adjustedTDEE – carbCalories – proteinCalories;
if (fatCalories < 0) {
// This can happen if carb/protein targets are too high for the calorie goal.
// For keto, fat is the primary energy source, so we should ensure it's positive.
// If negative, it means the user's protein/carb settings are too high for their calorie goal.
// We'll cap fat at 0 and adjust protein/carbs if necessary, but for simplicity,
// we'll just display the calculated (potentially negative) value and warn.
resultDiv.innerHTML = "Warning: Your carb and protein targets are too high for your calorie goal. Consider reducing protein or carbs, or increasing your calorie goal.";
fatCalories = 0; // Prevent negative fat grams
}
var fatGrams = fatCalories / 9;
// Calculate percentages
var totalMacroCalories = carbCalories + proteinCalories + fatCalories;
var carbPercentage = (carbCalories / totalMacroCalories) * 100;
var proteinPercentage = (proteinCalories / totalMacroCalories) * 100;
var fatPercentage = (fatCalories / totalMacroCalories) * 100;
// Display results
var resultsHtml = "
Your Daily Keto Macro Targets
";
resultsHtml += "
Estimated Daily Calories: " + adjustedTDEE.toFixed(0) + " kcal";
resultsHtml += "
";
resultsHtml += "
" + carbGrams.toFixed(0) + "gCarbohydrates (" + carbPercentage.toFixed(1) + "%)
";
resultsHtml += "
" + proteinGrams.toFixed(0) + "gProtein (" + proteinPercentage.toFixed(1) + "%)
";
resultsHtml += "
" + fatGrams.toFixed(0) + "gFat (" + fatPercentage.toFixed(1) + "%)
";
resultsHtml += "
";
resultsHtml += "
These are estimated targets. Individual needs may vary. Adjust as needed based on your progress and how you feel.";
resultDiv.innerHTML = resultsHtml;
}