Calorie Calculator

What is This Tool?

The Calorie Calculator computes your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) using the Mifflin-St Jeor equation, which is widely regarded as the most accurate formula for estimating caloric needs. It provides calorie targets for maintenance, mild weight loss, weight loss, and extreme weight loss, along with macronutrient breakdowns. All calculations run locally in your browser — no data is uploaded or stored.

How to Use This Tool

1. Choose your unit system — Metric (cm/kg) or Imperial (ft-in/lb).
2. Select your gender and enter your age.
3. Enter your height and weight in the selected unit system.
4. Choose your activity level from Sedentary to Extra Active.
5. View your BMR, TDEE, and calorie targets for different goals.
6. Select a macro ratio (Balanced, Low Carb, or High Protein) to see the protein, carbs, and fat breakdown for each calorie target.

Understanding the Formulas

• BMR (Basal Metabolic Rate): The number of calories your body burns at complete rest to maintain basic life functions like breathing and circulation.
• TDEE (Total Daily Energy Expenditure): Your BMR multiplied by an activity factor, representing the total calories you burn in a day including exercise and daily activities.
• Mifflin-St Jeor Formula: Male: 10 x weight(kg) + 6.25 x height(cm) - 5 x age + 5. Female: 10 x weight(kg) + 6.25 x height(cm) - 5 x age - 161.

Tips and Best Practices

• These are estimates — individual metabolism can vary by 5-15%. Use the numbers as a starting point and adjust based on actual results over 2-4 weeks.
• Do not drop calories below 1,500/day for men or 1,200/day for women without medical supervision. The calculator enforces these minimums.
• A deficit of 500 calories per day leads to approximately 1 pound (0.45 kg) of weight loss per week.
• Choose your activity level honestly — overestimating leads to higher calorie targets and slower progress.
• The High Protein macro preset is ideal for those doing strength training and wanting to preserve or build muscle.