Good Calorie Calculator

Daily Calorie Needs Calculator

Please fill in all fields with valid numbers.

function calculateCalories() { var age = parseFloat(document.getElementById('age').value); var gender = document.querySelector('input[name="gender"]:checked').value; var weight = parseFloat(document.getElementById('weight').value); var weightUnit = document.querySelector('input[name="weightUnit"]:checked').value; var height = parseFloat(document.getElementById('height').value); var heightUnit = document.querySelector('input[name="heightUnit"]:checked').value; var activityLevelMultiplier = parseFloat(document.getElementById('activityLevel').value); var goalAdjustment = parseFloat(document.getElementById('goal').value); var errorDiv = document.getElementById('error'); errorDiv.style.display = 'none'; // Hide previous errors if (isNaN(age) || age <= 0 || isNaN(weight) || weight <= 0 || isNaN(height) || height <= 0) { errorDiv.style.display = 'block'; document.getElementById('result').innerHTML = ''; return; } var weight_kg; if (weightUnit === 'lbs') { weight_kg = weight * 0.453592; } else { weight_kg = weight; } var height_cm; if (heightUnit === 'inches') { height_cm = height * 2.54; } else { height_cm = height; } var bmr; // Basal Metabolic Rate if (gender === 'male') { bmr = (10 * weight_kg) + (6.25 * height_cm) – (5 * age) + 5; } else { // female bmr = (10 * weight_kg) + (6.25 * height_cm) – (5 * age) – 161; } var tdee = bmr * activityLevelMultiplier; // Total Daily Energy Expenditure var finalCalories = tdee + goalAdjustment; var resultDiv = document.getElementById('result'); var disclaimer = ''; if (goalAdjustment === -1000 || goalAdjustment === 1000) { disclaimer = 'Important: Extreme calorie adjustments should only be pursued under the guidance of a healthcare professional or registered dietitian.'; } resultDiv.innerHTML = `

Your Estimated Daily Calorie Needs:

${Math.round(finalCalories)} Calories/day (Based on a Basal Metabolic Rate (BMR) of ${Math.round(bmr)} calories and a Total Daily Energy Expenditure (TDEE) of ${Math.round(tdee)} calories) ${disclaimer} `; }

Understanding Your Daily Calorie Needs

Knowing your daily calorie needs is a fundamental step towards achieving your health and fitness goals, whether you aim to lose weight, gain muscle, or maintain your current physique. Our Daily Calorie Needs Calculator provides an estimate based on several key factors unique to you.

What is a Calorie?

A calorie is a unit of energy. In nutrition, it refers to the energy people get from the food and drink they consume, and the energy they use in physical activity. Your body needs calories to perform all its basic functions, from breathing and thinking to moving and exercising.

How Does This Calculator Work?

This calculator uses the widely recognized Mifflin-St Jeor Equation to estimate your Basal Metabolic Rate (BMR), and then adjusts it based on your activity level to determine your Total Daily Energy Expenditure (TDEE). Finally, it factors in your specific goal (weight loss, maintenance, or gain) to provide a personalized calorie target.

1. Basal Metabolic Rate (BMR)

Your BMR is the number of calories your body burns at rest to maintain basic life-sustaining functions like breathing, circulation, cell production, and nutrient processing. It's the minimum amount of energy your body needs to simply exist. The Mifflin-St Jeor equation is considered one of the most accurate for estimating BMR:

• 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

As you can see, factors like age, gender, weight, and height significantly influence your BMR.

2. Total Daily Energy Expenditure (TDEE)

Your TDEE is the total number of calories you burn in a 24-hour period, including your BMR and the calories expended through physical activity. It's calculated by multiplying your BMR by an activity level factor:

• Sedentary: BMR × 1.2 (little or no exercise)
• Lightly Active: BMR × 1.375 (light exercise/sports 1-3 days/week)
• Moderately Active: BMR × 1.55 (moderate exercise/sports 3-5 days/week)
• Very Active: BMR × 1.725 (hard exercise/sports 6-7 days a week)
• Extra Active: BMR × 1.9 (very hard exercise/physical job/training twice a day)

3. Adjusting for Your Goal

Once your TDEE is established, we adjust it based on your desired outcome:

• Maintain Weight: Consume calories equal to your TDEE.
• Weight Loss: Create a calorie deficit (consume fewer calories than your TDEE). A deficit of 500 calories per day typically leads to a loss of about 0.5 kg (1 pound) per week.
• Weight Gain: Create a calorie surplus (consume more calories than your TDEE). A surplus of 500 calories per day typically leads to a gain of about 0.5 kg (1 pound) per week.

Example Calculation:

Let's consider a 30-year-old moderately active male, weighing 70 kg (154 lbs) and 175 cm (5'9″) tall, aiming for moderate weight loss.

1. BMR Calculation:
   BMR = (10 × 70) + (6.25 × 175) – (5 × 30) + 5
   BMR = 700 + 1093.75 – 150 + 5 = 1648.75 calories
2. TDEE Calculation:
   Activity Level (Moderately Active) multiplier = 1.55
   TDEE = 1648.75 × 1.55 = 2555.56 calories
3. Goal Adjustment (Moderate Weight Loss):
   Target = TDEE – 500 calories
   Target = 2555.56 – 500 = 2055.56 calories

So, this individual would aim for approximately 2056 calories per day to achieve moderate weight loss.

Important Considerations:

While this calculator provides a good estimate, individual calorie needs can vary due to genetics, body composition, hormonal factors, and specific health conditions. It's always recommended to consult with a healthcare professional or a registered dietitian for personalized advice, especially if you have underlying health issues or are considering extreme calorie adjustments.

Remember that calorie intake is just one piece of the puzzle. The quality of your calories (nutrient-dense foods), adequate protein intake, hydration, sleep, and consistent exercise all play crucial roles in overall health and achieving your body composition goals.