Keto Diet Calculator

Welcome to the Keto Diet Calculator! This tool is designed to help you determine your personalized macronutrient targets (carbohydrates, protein, and fat) to effectively follow a ketogenic diet. Whether your goal is weight loss, maintenance, or muscle gain, understanding your daily caloric and macro needs is crucial for success on keto.

What is a Ketogenic Diet?

A 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 in ketosis, 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?

While the general principle of keto is "low carb, high fat," the exact amounts of protein and fat you need can vary significantly based on your individual body composition, activity level, age, and goals. Calculating your macros ensures you're consuming enough protein to preserve muscle mass, enough fat to feel satiated and fuel your body, and few enough carbs to stay in ketosis. Guessing can lead to suboptimal results or even hinder your progress.

How Our Keto Calculator Works

Our calculator uses established formulas to estimate your Basal Metabolic Rate (BMR), Total Daily Energy Expenditure (TDEE), and then allocates your calories into the optimal macronutrient ratios for a ketogenic diet. Here's a breakdown:

Basal Metabolic Rate (BMR): This is the number of calories your body burns at rest to maintain basic bodily functions (breathing, circulation, cell production, etc.). 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 adjusted for your activity level. It represents the total number of calories you burn in a day, including exercise and daily activities.
Calorie Target: Based on your TDEE and your chosen goal (weight loss, maintenance, or gain), the calculator adjusts your total daily calorie intake.
Macronutrient Allocation:
- Net Carbs: We set a default low carb target (typically 20g) to ensure you enter and maintain ketosis. You can adjust this if you have a higher tolerance or specific needs.
- Protein: Protein intake is crucial on keto to preserve muscle mass, especially during weight loss. Our calculator estimates your lean body mass (LBM) and recommends a protein range (e.g., 0.8-1.0 grams per pound of LBM) to support your goals without kicking you out of ketosis.
- Fat: The remaining calories after accounting for carbs and protein are allocated to fat. Fat is your primary energy source on keto and helps with satiety.

Input Definitions

Current Weight (lbs): Your current body weight.
Height (feet & inches): Your height, used in BMR calculation.
Age (years): Your age, also a factor in BMR.
Gender: Influences BMR calculation.
Activity Level: Describes how active you are daily, affecting your TDEE.
- 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.
- Extremely Active: Hard daily exercise/sports & physical job.
Body Fat Percentage (% – Optional): An optional but highly recommended input for more accurate protein targets. If you don't know it, you can use online visual guides or body fat calipers. If left blank, the calculator will use a general estimate.
Keto Goal:
- Lose Weight: Eat at a caloric deficit (e.g., 20% below TDEE).
- Maintain Weight: Eat at your TDEE.
- Gain Weight: Eat at a caloric surplus (e.g., 10% above TDEE).
Net Carb Target (grams): Your desired daily net carb intake. 20g is a common starting point for strict keto.

Current Weight (lbs):

Height: feet inches

Age (years):

Gender: Male Female

Activity Level: 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) Extremely Active (hard daily exercise/sports & physical job)

Body Fat Percentage (% – Optional):

Keto Goal: Lose Weight (20% deficit) Maintain Weight Gain Weight (10% surplus)

Net Carb Target (grams):

Your Keto Macro Targets:

Basal Metabolic Rate (BMR): calories/day

Total Daily Energy Expenditure (TDEE): calories/day

Target Calories: calories/day

Net Carbs: grams ( calories)

Protein: grams ( calories)

Fat: grams ( calories)

Note: Protein target is based on 0.8-1.0g per pound of lean body mass. If Body Fat % was not provided, a general estimate was used.

.calculator-container { background-color: #f9f9f9; border: 1px solid #ddd; padding: 20px; border-radius: 8px; max-width: 600px; margin: 20px auto; font-family: Arial, sans-serif; } .form-group { margin-bottom: 15px; } .form-group label { display: block; margin-bottom: 5px; font-weight: bold; } .form-group input[type="number"], .form-group select { width: calc(100% – 12px); padding: 8px; border: 1px solid #ccc; border-radius: 4px; box-sizing: border-box; } .form-group input[type="radio"] { margin-right: 5px; } .form-group input[type="radio"] + label { display: inline-block; margin-right: 15px; } button { background-color: #007bff; color: white; padding: 10px 15px; border: none; border-radius: 4px; cursor: pointer; font-size: 16px; width: 100%; } button:hover { background-color: #0056b3; } .calculator-results { margin-top: 20px; padding: 15px; border: 1px solid #e0e0e0; border-radius: 8px; background-color: #eaf6ff; } .calculator-results h3 { color: #007bff; margin-top: 0; } .calculator-results p { margin-bottom: 8px; } .calculator-results p strong { min-width: 150px; display: inline-block; } .note { font-size: 0.9em; color: #555; margin-top: 15px; } function calculateKetoMacros() { // Get input values var currentWeightLbs = parseFloat(document.getElementById("currentWeight").value); var heightFeet = parseFloat(document.getElementById("heightFeet").value); var heightInches = parseFloat(document.getElementById("heightInches").value); var age = parseFloat(document.getElementById("age").value); var gender = document.querySelector('input[name="gender"]:checked').value; var activityLevel = document.getElementById("activityLevel").value; var bodyFatPercentage = parseFloat(document.getElementById("bodyFatPercentage").value); // Optional var ketoGoal = document.getElementById("ketoGoal").value; var carbTargetGrams = parseFloat(document.getElementById("carbTarget").value); // Input validation if (isNaN(currentWeightLbs) || currentWeightLbs <= 0) { alert("Please enter a valid current weight."); return; } if (isNaN(heightFeet) || heightFeet < 0 || isNaN(heightInches) || heightInches < 0 || (heightFeet === 0 && heightInches === 0)) { alert("Please enter a valid height."); return; } if (isNaN(age) || age <= 0) { alert("Please enter a valid age."); return; } if (isNaN(carbTargetGrams) || carbTargetGrams < 0) { alert("Please enter a valid net carb target."); return; } if (!isNaN(bodyFatPercentage) && (bodyFatPercentage 60)) { alert("Please enter a realistic body fat percentage (e.g., 5-60%)."); return; } // Convert weight to kg and height to cm for BMR calculation var currentWeightKg = currentWeightLbs * 0.453592; var totalHeightCm = (heightFeet * 30.48) + (heightInches * 2.54); // 1. Calculate BMR (Mifflin-St Jeor Equation) var bmr; if (gender === "male") { bmr = (10 * currentWeightKg) + (6.25 * totalHeightCm) – (5 * age) + 5; } else { // female bmr = (10 * currentWeightKg) + (6.25 * totalHeightCm) – (5 * age) – 161; } // 2. Calculate TDEE based on activity level var activityFactor; switch (activityLevel) { case "sedentary": activityFactor = 1.2; break; case "light": activityFactor = 1.375; break; case "moderate": activityFactor = 1.55; break; case "very": activityFactor = 1.725; break; case "extreme": activityFactor = 1.9; break; default: activityFactor = 1.2; // Default to sedentary } var tdee = bmr * activityFactor; // 3. Calculate Target Calories based on Keto Goal var targetCalories; var calorieDeficitPercentage = 0.20; // 20% deficit for weight loss var calorieSurplusPercentage = 0.10; // 10% surplus for weight gain if (ketoGoal === "lose") { targetCalories = tdee * (1 – calorieDeficitPercentage); } else if (ketoGoal === "gain") { targetCalories = tdee * (1 + calorieSurplusPercentage); } else { // maintain targetCalories = tdee; } // Ensure target calories don't go too low (e.g., below BMR for extreme deficits) if (targetCalories < bmr && ketoGoal === "lose") { targetCalories = bmr * 0.9; // Cap deficit at 10% below BMR to prevent unhealthy targets } if (targetCalories < 1200 && gender === "female") targetCalories = 1200; // Minimum for women if (targetCalories 0) { leanBodyMassLbs = currentWeightLbs * (1 – (bodyFatPercentage / 100)); proteinGrams = leanBodyMassLbs * proteinTargetPerLBM; } else { // Fallback if BF% is not provided: use a general protein target based on total calories // For keto, protein is typically 20-25% of total calories. var proteinPercentageOfCalories = 0.22; // 22% of target calories proteinGrams = (targetCalories * proteinPercentageOfCalories) / 4; // 4 calories per gram of protein } // Cap protein to prevent excessively high or low values if (proteinGrams > (currentWeightLbs * 1.0)) { // Max 1g per lb of total weight proteinGrams = currentWeightLbs * 1.0; } if (proteinGrams < (currentWeightLbs * 0.6)) { // Min 0.6g per lb of total weight proteinGrams = currentWeightLbs * 0.6; } var proteinCalories = proteinGrams * 4; // 4 calories per gram of protein var remainingCalories = targetCalories – carbCalories – proteinCalories; // Ensure remaining calories for fat are not negative if (remainingCalories < 0) { remainingCalories = 0; } var fatGrams = remainingCalories / 9; // 9 calories per gram of fat var fatCalories = fatGrams * 9; // Display results document.getElementById("bmrResult").innerText = Math.round(bmr); document.getElementById("tdeeResult").innerText = Math.round(tdee); document.getElementById("targetCaloriesResult").innerText = Math.round(targetCalories); document.getElementById("netCarbsGramsResult").innerText = Math.round(carbTargetGrams); document.getElementById("netCarbsCalResult").innerText = Math.round(carbCalories); document.getElementById("proteinGramsResult").innerText = Math.round(proteinGrams); document.getElementById("proteinCalResult").innerText = Math.round(proteinCalories); document.getElementById("fatGramsResult").innerText = Math.round(fatGrams); document.getElementById("fatCalResult").innerText = Math.round(fatCalories); // Show the results section document.getElementById("ketoResults").style.display = "block"; } // Initial hide of results section document.addEventListener('DOMContentLoaded', function() { document.getElementById("ketoResults").style.display = "none"; });

Example Calculation:

Let's consider a 30-year-old male, 5'10" (70 inches) tall, weighing 180 lbs, with a body fat percentage of 20%, who is moderately active and wants to lose weight with a 20g net carb target.

Inputs:
- Current Weight: 180 lbs
- Height: 5 feet 10 inches
- Age: 30 years
- Gender: Male
- Activity Level: Moderately Active
- Body Fat Percentage: 20%
- Keto Goal: Lose Weight
- Net Carb Target: 20 grams
Calculation Steps:
1. Convert Units:
  - Weight: 180 lbs * 0.453592 = 81.65 kg
  - Height: (5 * 30.48) + (10 * 2.54) = 152.4 + 25.4 = 177.8 cm
2. BMR (Mifflin-St Jeor for Male):
  - (10 * 81.65) + (6.25 * 177.8) – (5 * 30) + 5
  - 816.5 + 1111.25 – 150 + 5 = 1782.75 calories
3. TDEE (Moderately Active, factor 1.55):
  - 1782.75 * 1.55 = 2763.26 calories
4. Target Calories (20% deficit for weight loss):
  - 2763.26 * (1 – 0.20) = 2763.26 * 0.80 = 2210.61 calories
5. Macronutrient Allocation:
  - Net Carbs: 20g * 4 cal/g = 80 calories
  - Lean Body Mass (LBM): 180 lbs * (1 – 0.20) = 180 * 0.80 = 144 lbs
  - Protein (0.9g/lb LBM): 144 lbs * 0.9 g/lb = 129.6 grams
  - Protein Calories: 129.6g * 4 cal/g = 518.4 calories
  - Remaining Calories for Fat: 2210.61 – 80 – 518.4 = 1612.21 calories
  - Fat: 1612.21 calories / 9 cal/g = 179.13 grams
Estimated Results:
- BMR: ~1783 calories/day
- TDEE: ~2763 calories/day
- Target Calories: ~2211 calories/day
- Net Carbs: 20 grams (80 calories)
- Protein: 130 grams (520 calories)
- Fat: 179 grams (1611 calories)

These numbers provide a solid starting point for tracking your macros on a ketogenic diet. Remember to adjust based on how you feel, your energy levels, and your progress towards your goals.

Tips for Success on Keto:

Track Everything: Especially in the beginning, use a food tracking app to accurately log your intake.
Stay Hydrated: Drink plenty of water, as keto can lead to increased water and electrolyte loss.
Electrolytes are Key: Supplement with sodium, potassium, and magnesium to prevent "keto flu."
Listen to Your Body: Adjust your macros if you're feeling overly hungry, tired, or if your progress stalls.
Focus on Whole Foods: Prioritize nutrient-dense, whole foods like fatty meats, fish, eggs, avocados, nuts, seeds, and low-carb vegetables.

Use this calculator as a guide to kickstart your keto journey, and remember that consistency is key!

What is a Ketogenic Diet?

Why Calculate Your Macros?

How Our Keto Calculator Works

Input Definitions